# Nailer (Pneumatic & Cordless) Hewn Tool Library · https://hewn.build/tools/nailer-pneumatic-cordless Corrected: An independent reviewer read this entry and found corrections. They have been applied to the text, and the reviewer re-checked the correction that mattered most for safety and found it done; the others have not been re-checked yet. The list at the end is the record of what changed. Cite as: "Nailer (Pneumatic & Cordless)." Hewn Tool Library, hewn.build/tools/nailer-pneumatic-cordless. Reviewed 2026-09-10. --- ## Identity **Name:** Nailer, commonly "nail gun" in trade and consumer speech; manufacturers use "nailer" in product names (framing nailer, finish nailer, roofing nailer). "Fastener-driving tool" is the broad family term; "nailer" means a tool designed for nails or pins. A stapler is a sibling, not the same tool with a different fastener: driver, magazine, nose, actuation and power source may be analogous, but fastener geometry and evaluated applications differ. **Family / category:** A mechanized, trigger-fired fastening tool that drives collated nails or pins through a magazine and a driver blade, replacing the repeated hammer blow with a single stored-energy stroke. Sibling in mechanism to [[Staple Gun]] (magazine, driver blade, workpiece-contact nose) but a different fastener class for a different purpose. Powder-actuated (cartridge) tools are a different, more hazardous class, outside this entry and outside the OSHA/NIOSH nail gun guide's scope. **One line:** The trigger-fired tool that drives a nail in a fraction of a second from stored energy instead of a swung hammer, central to how fast a modern framing crew works, and, per OSHA, a tool whose injuries hospitalize more construction workers than any other tool-related injury. **Two questions, not one.** "Cordless" is not an architecture. Describe every tool on two levels: - **Power supply:** hose-fed compressed air; replaceable combustible fuel cell plus a battery for ignition and fan; or rechargeable battery alone. - **Drive mechanism:** pneumatic piston; combustion-gas piston; and, for battery-only tools, examples such as a flywheel, a sealed air/gas spring, a mechanical spring, or a solenoid where documented. The list is not exhaustive, and each mechanism is tied to a named model and its manual. - Examples from the review: Makita describes an air-spring system on its DBN900/XNB framing tools, and DeWalt describes a spinning flywheel on the DCN690 `[manual, relayed]`. Those are two different mechanisms under one "battery-only" label. The architecture affects weight, firing delay, service, recoil feel, jam clearing and stored-energy hazards, so it is first-class matching data. --- ## ✦ How NOT to use it **Safety first: the minimum operating sequence.** The spine is OSHA/NIOSH, *Nail Gun Safety: A Guide for Construction Contractors* (NIOSH 2011-202 / OSHA 3459), read in this pass; it covers pneumatic tools and says its principles also apply to gas, electric and hybrid nailers, and it excludes powder-actuated tools. Items marked `[manual, relayed]` rest on the reviewer's description of the Paslode or Makita manual, which was not read here. The exact model's manual wins over this list. 1. **Actuation.** Prefer a full-sequential nailer and verify the selected mode before use ("The full sequential trigger is always the safest trigger mechanism for the job"). Use the exact terminology in the model manual; not every manual uses "bump." 2. **Read and test.** Read the exact manual and get task-specific training. Inspect the workpiece-contact element and other safety devices, test them exactly as the manual directs, and never disable or remove them `[manual, relayed]`. The contact element is an interlock, not a guarantee. 3. **Inspect the tool and the work.** Check the tool, hose and fittings or battery and fuel system, magazine and fasteners. Check the work for knots, metal connectors, existing fasteners, concealed electrical, gas or water, thin backing, people and openings behind the target. 4. **PPE.** Safety glasses or goggles marked ANSI Z87.1, hearing protection, and head and foot protection as the manual and site rules require (OSHA/NIOSH lists hard hats, eye and hearing protection, and safety shoes). 5. **Line of fire and hands.** Keep the tool and every person out of the possible fastener path ("Always shoot nail guns away from your body and away from co-workers"; set up operations so workers are not in the line of fire of co-workers' tools). For placement work keep the free hand at least 12 inches from the nailing point, or clamp the work. Reposition, or use a hammer or positive-placement tool, for awkward, overhead, tight-space, metal-connector or uncontrolled toenailing work. 6. **Finger off the trigger** when not intentionally firing, when carrying or moving the tool, and when handing it off. Fire only after the contact element is positioned. Do not carry a contact-actuation tool with the trigger depressed. 7. **Isolate the energy source** before loading where the manual requires it, clearing a jam, adjusting, servicing, handing the tool to another person, climbing, or leaving it unattended (OSHA/NIOSH: disconnect compressed air for exactly these). Isolation differs by architecture; see below. A jammed mechanism may remain under spring or gas pressure. 8. **Do not fire** into knots, existing fasteners, unsupported edges or concealed hazards. Use only manual-approved fasteners, pressure, batteries, fuel and parts, at the correct pressure or setting. 9. **Stop** on double-fire, ricochet, unexpected recoil, misfeed, air or fuel leak, damaged safety element or any malfunction, and stop using a damaged tool. 10. **After a penetration injury,** seek prompt medical evaluation (OSHA/NIOSH: about 1 in 4 nail gun hand injuries involve structural damage, embedded debris can cause infection, and barbs can cause secondary injury if a nail is removed incorrectly). Do not pull an embedded or barbed fastener casually; seek emergency help for eye, head, chest, abdomen, joint or neurovascular involvement. **Isolation by architecture (keep these separate).** - **Pneumatic:** disconnect the air hose at the tool and control stored pressure in the hose and compressor; hose, coupling, pressure and compressor hazards are their own set. - **Fuel-cell:** remove the battery and the fuel cell; ventilate; Paslode warns of carbon monoxide, prohibits use near combustible chemicals or vapors, and sets heat and storage limits for the fuel and battery `[manual, relayed]`. A jam can leave gas pressure in the mechanism. - **Battery-only:** remove the battery or use the model's specified disable procedure; the drive may hold spring, air-spring or flywheel energy. Charging, damaged-pack and thermal-runaway hazards go to the battery and tool manual `[manual, relayed]`. **Not-for:** - **A finish nailer used for structural framing.** Finish nails are not specified structural fasteners; an inspector will not accept a framed wall on them (trade-guide phrasing, finepowertools.com and similar, medium confidence, not read). - **A framing nailer used on trim.** Firing framing nails into thin baseboard can split the board along its length because the nail is much larger than a finish nail (aggregated trade phrasing, medium confidence, not read). - **A coil roofing nailer used as a framing nailer, or the reverse.** Roofing tools are built for short, wide-head roofing nails and cannot drive a nail long enough for sheathing or framing (Fine Homebuilding, Garage Journal and finepowertools.com threads, three forum-tier sources). **Dangerous, misuse and injury record (with date range, population and evidence type stated).** - **OSHA's claim, narrowly:** "Injuries resulting from use of nail guns hospitalize more construction workers than any other tool-related injury" (OSHA, Nail Gun Safety page, read in this pass). OSHA also cites a study in which 2 out of 5 residential carpenter apprentices had a nail gun injury over four years, and says such injuries are often not reported or properly treated. This is not the same as "most injury-documented hand power tool," and that wording is withdrawn. - **Estimates, with their vintage.** The older surveillance figure of about 37,000 emergency-department visits a year, 68% of them workers, is the figure the original run quoted from OSHA's page; it was not on the page version read in this pass and is carried as `[relayed from the reviewer and the original run]`. The 2006–2011 NEISS-Work study (Lipscomb et al., *American Journal of Industrial Medicine*, 2015) estimated about 14,000 worker and 11,000 consumer injuries a year `[relayed from the reviewer]`, with worker injuries falling sharply in the 2008–2011 construction downturn. - **Contact trigger risk.** OSHA states "the risk of a nail gun injury is twice as high when using a multi-shot contact trigger" than with a single-shot sequential trigger; the OSHA/NIOSH guide reports this roughly twofold overall acute-injury risk including after training `[relayed from the reviewer for the "after training" detail]`. - **Double-fire.** CPWR/eLCOSH explains that a contact-trip gun reloads after discharge and, with the finger on the trigger, fires again if the nose touches anything; the two trigger types look alike, and some tools switch between modes `[relayed from the original run's reading of eLCOSH; not re-read here]`. The same summary reports interviews with more than 400 injured carpenters, with ricochet and projectile nails dominating and about 12% of injuries to people not using the gun `[relayed, original run]`; population and period are those of that research, not the industry. - **Case examples.** CPWR/eLCOSH hosts a video, "Death in the Sierra," on the death of Manuel Murillo in Portola, California, from inadvertent firing of a nail gun (produced by Andy Alfaro of the *Sacramento Bee*), and "Just Driving Down the Street," on a bystander struck in the eye. The OSHA/NIOSH guide also carries fatality and worksite examples. The litigation-marketing anecdote in the earlier version has been removed. - **Where injuries land.** Clinical literature reviews (litfl.com, citing Pierpont 2008, Horne and Corley 2007 in *Injury*, Hoffman et al. 1997 in *American Family Physician*) report about 65% of nail gun injuries to the hand, most to the non-dominant hand, about 75% soft-tissue and 25% with structural damage; percentages vary by study population `[relayed from the original run; not re-read]`. The non-dominant hand is the one a user is tempted to hold work with, which is why the 12-inch rule matters. - **Pneumatic nailers are not firearms, but are still lethal.** NIOSH measured pneumatic nailer velocities of roughly 98–121 ft/s in its own experiment (other reports 66–98 ft/s) and says deaths and serious injuries have occurred, so these tools should be handled with firearm-level care (read in this pass: NIOSH, "First NIOSH Comic Helps Dispel Internet 'Myth'"). The oft-repeated 1,400 ft/s figure belongs to cartridge-powered powder-actuated tools, which are outside this entry, and the earlier comparison to injury thresholds is deleted; it is not needed to establish that nails penetrate hands, eyes, bone and organs. - **Institutional response.** The OSHA/NIOSH guide (September 2011) followed a unanimous motion by industry, state and labor stakeholders on OSHA's construction advisory committee. NIOSH's 2015 bulletin ("NIOSH, Nail Guns, and Consensus Standards: Where We Stand") criticized the 2015 consensus standard's weaker labeling and exemptions; ANSI lists ANSI/ISANTA SNT-101-2024 as the revision, whose requirements were not reviewed here `[relayed from the reviewer]`. **Damaging: overdriving.** Overdriving can reduce the capacity and ductility of wood structural panel shear walls and diaphragms. The effect is assembly-specific: it depends on the panel, fastener, spacing, edge distance, framing, and the fraction and depth of overdrives. Inspect against the project documents and use APA Technical Topic TT-012, an applicable evaluation report and the engineer of record for assessment or repair. APA TT-012 gives conditional assessment and corrective-fastening guidance by depth and proportion of overdriven fasteners, not a universal joint-loss curve; the APA page read in this pass is a summary and does not state the criteria. One specimen study, Judd and Fonseca, *Journal of Structural Engineering* 2002, on oriented strand board shear walls with overdriven sheathing nails, reports shear-wall strength reductions of 5%, 12% and 24% at 1.6, 3.2 and 4.8 mm overdrive, with displacement capacity changing by +1%, -22% and -56% `[relayed from the reviewer; abstract not fetched]`. Those values apply only to that specimen configuration and response measure. The earlier 9%/13%/22% series did not match the located study and is removed, as is the claim that guns are commonly calibrated slightly overdriven as an industry habit; no authoritative source found supports it. WoodWorks' "Using Gun Nails in Wood-Framed Shear Walls and Diaphragms" supports specifying shank diameter, length, head diameter, yield strength, spacing and evaluation-report capacities rather than penny size or tool fit `[relayed from the reviewer]`. **Beginner-trap:** - **Losing the pause the hammer imposed.** How-to material names skipping layout and rushing without inspecting the tool as the classic new-user failure; the gun's speed removes the pause a swung hammer imposed (low-medium confidence, generic how-to tier). - **Depth-setting drift.** A depth setting right for the first shots can stop being right as material thickness or density changes; check it on representative material and re-check as conditions change. - **Dry-firing.** Firing with an empty or nearly empty magazine can damage the driver blade and O-rings and cause sharper recoil; many tools ship with a dry-fire lockout (a Ryobi model is cited, forum-tier). - **Toenailing angle compounding recoil.** Recoil in a less-braced angled position is more likely to bring the tool back toward the face in tight quarters, and a new worker's instinct to push harder is the behavior CPWR names as a contributor to double-fire injuries. - **Assuming bump-fire is needed for speed.** The controlled study (see Human side) found a small project-level cost for the sequential trigger, not a speed gain worth the added risk. **Lineage-misuse:** - **Nailer-trained carpenters and hand-nailing technique.** The plausible pattern (crews trained on nailers lacking a hand-nailer's feel for grain, knots and splitting) is inherited from [[Framing Hammer (California Framer)]], which also found no sourced account. It is carried as an open gap, not a fact. - **Roofing nailer mistaken for framing nailer, or the reverse.** The shared coil silhouette invites it, and the mismatch in fastener length and head design makes the consequence immediate (forum-tier, three sources). - **A stapler mistaken for a nailer** ([[Staple Gun]]): structurally plausible, no sourced account found; speculation. - **A cordless nailer handled as if it behaved like its pneumatic ancestor.** Paslode's history frames the 1986 Impulse as an architectural break; no sourced account of operator confusion from recoil or weight differences was found. --- ## Correct use **Genuinely good at:** fast, repetitive, compatible fastening where a matched nailer replaces repeated hammer driving, and driving in tight framing bays where a full hammer swing has no room. Toenailing is an awkward, higher-risk operation; OSHA/NIOSH advises repositioning, or using a hammer or positive-placement tool, for awkward, overhead, tight-space and uncontrolled toenailing work. **Hands and work.** A nailer can be operated with the dominant hand, but the other hand must remain outside the possible fastener path. Secure small, narrow, unstable or placement-critical work with clamps or a fixture. OSHA/NIOSH: "For placement work, keep hands at least 12 inches away from the nailing point at all times," and "Consider using clamps to brace instead of your hands." Nails can follow grain, deflect, ricochet, miss the receiving member or pass through thin stock. Free-hand positioning is not an advantage of this tool. **How to use it well:** select the connection and fastener first, then a tool approved to drive it; run the safety sequence below before the first shot; set drive depth deliberately and re-check it as material thickness or density changes; and use a full sequential trigger wherever available (see Human side for what the controlled study did and did not show about its cost). --- ## ✦ Matching (the workbench's first read) **Routing warning:** select the fastener and the connection requirement first, then choose a tool approved to drive it. For structural shear walls, diaphragms, connectors, treated lumber, exterior exposure or fire-rated assemblies, project specifications and evaluation reports override generic trade categories. This entry does not imply that one tool spans these uses. **Does:** drives a nail in a single trigger-actuated stroke using stored compressed air, combustion gas or another stored mechanical energy. Verbs: **fasten, frame, sheathe, nail off, toe-nail, repeatedly.** The operator's other hand stays clear of the fastener path; work is held with clamps or a fixture when it is small, narrow, unstable or placement-critical. **Suits (keyed by variant; do not collapse them):** - **Framing nailer:** wall, floor and roof framing, subfloor, sheathing nail-off, deck and outbuilding framing, where the drawings or specification accept the fastener and tool. - **Coil roofing nailer:** shingle and underlayment attachment per the roofing manufacturer and project specification. - **Coil siding/fencing nailer:** siding and fence pickets, subject to substrate, corrosion exposure and manufacturer instruction. - **Finish/trim nailer:** trim, casing, cabinet installation; describe the holding role and substrate rather than making a universal nonstructural claim. - **Brad/pin nailer:** delicate trim and small moldings, often with glue. - **Positive-placement connector nailer and flooring nailer:** added as separate branches; use the connector or flooring manufacturer's specification. **Kit-fit, pairs with:** the [[Air Compressor]] and hose for pneumatic tools; for fuel-cell models, the fuel cells and battery; for battery-only models, the model's own battery pack. Fasteners are specified by shank diameter, length, head diameter/style, material/coating, collation type and angle, and the applicable code, design or evaluation report. "Crown" is staple terminology and does not apply to nails. Cross-brand fasteners can be compatible when the tool manual's full dimensional and collation specification is met; branding alone is not the rule. **Kit-fit, substitutes for (conditional):** for compatible repeated fastening, a matched nailer can replace repeated hammer driving. Keep a hammer or other tool for alignment, setting isolated proud nails where allowed, removal, and operations the nailer cannot access. Nailers do not perform layout, adjustment, nail removal or demolition. Follow connector, fastener, tool, code and engineer requirements; do not assume either hand- or power-driving is inherently accepted. Approved positive-placement nailers and specified collated fasteners can be used for some metal connectors. **Kit-fit, what can displace it:** in defined applications, screws, automated fastening systems, off-site panelization and other connection methods can take the place of nailing. The earlier statement that nothing displaces the nailer was a search negative and is withdrawn. **Not-for (project-keyed):** - A finish or brad nailer for structural framing, and a framing nailer on thin trim. - Any gauge class swapped for another; tool fit is not design approval. - Bump (contact) actuation by a user who does not understand double-fire; use full-sequential mode where the tool allows it and verify the selected mode before every use. - Any use that places a hand, a person or a face in the possible fastener path, or that disables the workpiece-contact element. **Access:** training and model-manual review required; full-sequential mode preferred; inexperienced users should practice on secured scrap at bench height with the line of fire cleared. Easy trigger force is not usability: safe placement, recoil control, grain and fastener-path judgment, mode identification, work-at-height controls and jam isolation require training. The sequential-versus-contact distinction is a first-class access-gate fact for any Hewn user matched to this tool. **Revival:** the same revival logic as [[Claw Hammer]] and [[Framing Hammer (California Framer)]] applies: quieter work near sleeping occupants, heritage and reproduction work, and Larry Haun's preference for the hammer's control in finish situations (secondary-source, unverified; see research notes). **Schema fields this entry still owes** (per the reviewer; to be filled variant by variant from current manuals): power source and drive mechanism; fastener diameter, length, head style, material/coating and collation; magazine angle, format and capacity; actuation modes and default; approved substrates and applications; operating pressure range for pneumatic models; depth adjustment and test-fastening requirement; connector approval; required energy-isolation steps; fuel-cell ventilation and fire restrictions; code, evaluation-report and corrosion constraints. --- ## Anatomy - **Magazine** — holds collated fasteners in stick (strip) or coil form; a spring-loaded pusher/follower advances the strip toward the drive track — the same general mechanism as [[Staple Gun]]'s own feeder, cross-tool. - **Nose / contact trip (workpiece contact element)** — a spring-loaded element at the muzzle that must press against the workpiece to permit firing. On pneumatics, per a directly-relevant 1990 patent (**US 4,907,730**, Jean-Paul Dion, identified via patent search, not independently read in full text this run), this is a mechanical valve interlock — "a feeler disc" that must contact the ground/workpiece to open a needle valve in the firing channel. On the Impulse combustion architecture, per Wikipedia's mechanism description (citing Fine Homebuilding, "How It Works: Cordless finish nailer," 2011-05-19) and corroborated by US 4,403,722's own claims, pressing the contact tip physically seals the combustion chamber and triggers metered fuel injection — the contact trip is part of the combustion cycle itself, not merely a safety switch layered on top of it. - **Driver blade** — the hardened steel blade struck by the piston that directly contacts and drives the fastener; alignment with the nail channel is required for reliable firing (same principle as [[Staple Gun]]'s driver blade). - **Piston** — in pneumatics, driven by a burst of compressed air released past a valve; in the Impulse, driven directly by combustion-gas pressure (US 4,403,722: "A piston connected to a fastener driver is slidably mounted within a cylinder to move reciprocally... through a driving and a return stroke"). - **O-rings / seals** — maintain the pressure seal in the piston/cylinder assembly; a documented wear-and-service item on vintage pneumatics (a 2010s-era retail listing for a Paslode GN-212/214/238 "O-Ring Kit," found via search — a concrete, dated commercial confirmation that this is a real, named service part, not an inferred one). - **Combustion chamber, spark plug, fuel cell, and purge fan (cordless/combustion architecture only)** — the combustion chamber forms at the cylinder's upper end and is sealed by the lifting-rod valve when the contact tip engages the work; a piezo-electric spark plug ignites a metered fuel/air charge from a replaceable pressurized fuel cell (per Paslode's own 2021 fuel Safety Data Sheet, archived via Wayback Machine and relayed through Wikipedia, the fuel is a mixture of propene and but-1-ene, each cell rated for roughly 1,000 rounds); a continuously-running electric fan purges exhaust gas after firing and mixes the next charge (US 4,403,722; Wikipedia). - **Depth-of-drive adjustment** — a dial or wheel that alters how far the nose/contact-trip assembly can travel before the driver reaches full extension, setting flush vs. countersunk drive depth. No specific manufacturer patent or document naming this mechanism directly was independently fetched this run — carried as general, well-attested trade/mechanical knowledge rather than a single sourced primary document, an honest gap. - **Trigger mechanism — sequential vs. bump (contact) fire, the tool's single most safety-consequential mechanical distinction.** A **full sequential trigger** fires only if the contact-trip element is pressed first, then the trigger pulled; both must be released and re-engaged in that order to fire again — it cannot be bump-fired. A **bump / contact trigger** is held squeezed continuously while the operator taps or bounces the tool's contact trip along the work, firing a nail on each contact (nailgundepot.com/nail-gun-network and safetymattersweekly.com, converging trade-safety-literature description, not a single primary citation). CPWR/Duke's own explainer (elcosh.org, fetched directly) adds a genuinely dangerous, underdiscussed detail: **"the two types look exactly alike, so workers cannot tell the difference between the contact trip and sequential triggers"** — and some current tools can switch between modes, compounding the confusion. See How NOT to Use It, Dangerous, for the documented injury consequence of this mechanism. --- ## Variations (living) | Variant | Distinguishing feature | Trade / use | Source | |---|---|---|---| | Framing nailer | Specified by shank diameter, length, head diameter/style, material/coating, collation type and angle, not by a gauge range; stick or coil magazine; high drive force | Structural wall/floor/roof framing, subfloor, sheathing, decks — the anchoring variant this entry is built around | Nail Gun Depot pricing/product data; JLC/Carlson trade history | | Finish nailer | 15–16 gauge, smaller hole, less structural claim | Trim, casing, cabinet installation | Wikipedia (Paslode Impulse); trade retail sources | | Brad nailer | 18 gauge, minimal hole | Delicate trim and small moldings | Trade retail sources | | Pin nailer | 23 gauge, often headless, positioning strength only | The most delicate finish work, typically paired with glue for real holding strength | Trade retail sources | | Roofing nailer (coil) | Wide-head roofing nails, coil-fed; typical capacity is a short fastener length (about 1¾" in the original sources; that figure is a fastener-length capacity, not a drive depth) | Asphalt shingle/underlayment attachment at high volume | Max Co. company history ("world's first dedicated roofing nailer," 1982, self-sourced, not independently corroborated); trade forums | | Coil siding/fencing nailer | Coil magazine, marketed and used as one combined category | Siding installation; fence picket work, where the substrate, corrosion exposure and manufacturer instruction allow | nailgundepot.com; DeWalt product listings; Contractor Talk forum | | Positive-placement connector nailer | Tool and nose designed to place nails through metal connector holes | Metal framing connectors, where the connector manufacturer and project documents specify a tool-driven nail | Added per the reviewer; no source read in this pass | | Flooring nailer | Mallet- or trigger-actuated tool for nailing hardwood flooring; US 3,542,273 (Hedrick, 1970) is an early example in the original sources | Wood flooring | Added per the reviewer; patent not read | | Palm nailer | Compact, palm-held rather than gripped like a gun; magazine-fed or single-shot | Tight/awkward spaces a full-size nailer can't fit — joist hangers, toe-nailing | US Patent 6,443,348 B2, "Palm nailer with magazine" (provisional filed Dec. 9, 1999) — identified via patent search, not independently read in full text this run | | Coil magazine (format) | Nails joined by wire or synthetic-resin plates wound into a flat coil, ~200–300 nails per load, indexing feed mechanism; more universal cross-brand fastener compatibility | Higher-volume framing, roofing, and pallet work; heavier tool | Fine Homebuilding, "Pneumatic Framing Nailers: Why Choose Coil over Stick?"; Everwin/ToolsLiving trade pages | | Stick / strip magazine (format) | Nails collated at an angle in a straight strip, typically 20–40 nails per stick, two sticks per load; must match the nail's specific collation angle/style to the tool | Lighter-weight tool, more common in finish work | Same sources | | Pneumatic (power supply: hose-fed compressed air) | External compressor and hose; air-pressure-driven piston | The long-standing architecture | Paslode and Max company histories (self-history); Carlson | | Combustible-fuel cordless (power supply) | Replaceable fuel cell metered into a combustion chamber, ignited by a battery-powered spark, with a fan; no hose or compressor but battery charging and periodic fuel-cell replacement (about 1,000 rounds per cell per Paslode's SDS as relayed) | Framing and finish work away from a compressor line | Paslode Impulse line, 1986 to present; US 4,403,722 is one early anchor, not proof of lineage for every model | | Battery-only cordless (power supply), drive mechanism varies | No fuel cell and no hose. Drive mechanism is model-specific: examples are a flywheel (DeWalt DCN690) and a sealed air/gas or air-spring system (Makita DBN900/XNB framing tools), plus mechanical-spring or solenoid designs where documented. Not one architecture, and not an exhaustive list | Framing and finish work without compressor or fuel | Makita product page and DeWalt support page, `[manual, relayed]` from the reviewer; verify against each model's manual | --- ## Trades - **Framing/production carpentry** — the tool's home turf and the trade whose economics it rewrote (see Human side). - **Roofing** — coil roofing nailers, a distinct fastener class and technique culture from framing. - **Siding and fencing** — frequently served by the same coil-nailer product category. - **Trim/finish carpentry and cabinet installation** — finish and brad nailers, a lighter-gauge, lower-force branch of the same tool family. - **Pallet and crate production** — the deep historical root of bulk mechanized nail-driving (Doig, 1862, per Carlson's trade history), still a live industrial application of collated-nail technology today, though not independently documented at the modern-tool level this run. --- ## Lineage **Ancestors — the hand hammer and nail, and a real, dated, named line of hand-actuated bulk-nailing machines that precede true pneumatic firing.** The direct ancestor is the hand-swung hammer driving loose nails — already documented in this corpus's [[Claw Hammer]] and [[Framing Hammer (California Framer)]] entries. Between the hammer and the modern trigger-fired nailer sits a genuine, dated mechanical lineage, per Don Carlson's trade history ("A Brief History of Portable Nail Guns," *Journal of Light Construction*, 2018-12-14, adapted from his self-published *The History of the Nailing and Stapling Business*; Carlson is Chairman of Carlson Holdings, a fastening-industry distributor, and writes that he has been involved in the stapling and nailing industry since 1947). This is one named trade historian's account, not independent primary proof of any "first"; the items below are attributed to him: - **1862 — Doig Manufacturing Company:** Carlson reports Doig as building "the first stationary machine that fed and drove bulk nails" — multi-head industrial nailing machines for pallets and crating. The original 1862 patent itself was not independently located and read this run — an honest gap in a claim that otherwise anchors the whole lineage. - **1907, Robbinsdale, Minnesota** — Carlson reports "the first commercialized, fully portable nail gun": a hand-held, bulk-fed nailer whose shaken hopper randomly fed one round-head shingle nail down a shoot, driven by the operator striking the tool's plunger with a two-faced mallet (rawhide face to drive, steel face to finish-set). It failed commercially because it effectively needed three hands — hold the shingle, hold the nailer, swing the mallet — a clean, named, sourced early failure mode, exactly the kind of "form follows failure" data point this corpus values. Carlson notes no surviving photograph of the tool has been located — an honest gap in his own account, carried here rather than papered over. **Descendants:** none identified — the nailer's own architecture is still actively branching (see the three power-architecture split under Variations) rather than being superseded by a wholly different tool. **Contemporaries — the staple gun, a genuine sibling by mechanism, not by fastener.** [[Staple Gun]] shares this tool's core mechanism (magazine, spring-loaded pusher, driver blade, contact-trip nose) and, per Carlson's trade history, a shared corporate lineage: the same industrial-stapler manufacturers who had already solved bulk fastener-feeding and pneumatic firing for staples were the ones positioned to extend that technology to nails once the driving-force problem (see History) was solved. The two tools are not interchangeable (see How NOT to use it, Lineage-misuse) but they are close cousins, closer than either is to the hand hammer. --- ## Lineage tree touch No dedicated fastening-tool-family lineage tree currently exists in this corpus (the same gap already noted in [[Planishing Hammer]] for the hammer family) — [[Staple Gun]], [[Air Compressor]], and [[Framing Hammer (California Framer)]] carry no lineage-tree-touch sections of their own, so none is created here either; flagged as a future-structure gap rather than an invented one. Light touch made instead directly to the three citing entries: [[Air Compressor]]'s pneumatic-nailer and cordless-Impulse mentions upgraded to a live wikilink pointing at this entry; [[Framing Hammer (California Framer)]]'s "pneumatic and cordless framing nailer" descendant mention upgraded to a live wikilink; [[Claw Hammer]]'s existing [CH56] "Nail Gun vs Hammer" citation left as-is (already a full reference, not a bare mention) with a cross-link added in this entry's own frontmatter instead. ## History **Evidence ladder, not a contest of "firsts."** The claims below come from three tiers: one trade historian's account (Carlson), manufacturers' own company histories, and a primary patent. The first two are attributed, not resolved. Each claim says which category it means (stationary or portable, bulk-fed or collated, pneumatic or hammer-assisted, production or jobsite, commercially successful), because the "first" depends on the category. **Origin claims that do not agree.** - **Paslode states** that its 1959 light-duty upholstery tacker was "the world's first pneumatic tool" and that the **GN-212** (1962, Skokie, IL, then a division of Signode Corporation) was "the world's first pneumatic nailer" (Paslode UK, "40 Years of Innovation"). Taken literally the 1959 phrase is far too broad, since pneumatic tools long predate 1959; the intended category appears to be a pneumatic fastening tool, and it is preserved here only as a quoted company claim. The GN-212 claim cannot stand beside Carlson's earlier pneumatic examples unless the category is defined more narrowly. - **Max Co., Ltd. states** that its T2-A, released in 1962, was Japan's first air nailer. Its own page says that tool drove staples and that the company later unified "air tacker" terminology under "air nailer." That is a narrower, Japan-only claim and not evidence of independent invention of the same nail-driving class as the GN-212. The earlier version of this entry called the two "parallel invention"; that wording is withdrawn. - **Carlson reports** earlier pneumatic work: **1944**, Morris Pynoos building a pneumatic nailer for Howard Hughes to assemble wooden parts of the H-4 flying boat; **1951–52**, Bill Burnison's Nu Matic Nailer in Los Angeles, which he calls the first commercially successful portable nailing machine for jobsite construction (bulk-fed, for roof-deck boards). No photograph of the Pynoos tool is known, by Carlson's own account. These are attributed claims until period patents, catalogs, dated photographs or Hughes records are found. **The recoil problem, as Carlson tells it (1957–58).** Carlson says porting compressed air through a trigger valve worked for staples up to about ⅝" but was too slow to drive a full-length nail without violent recoil, and names three competing fixes that failed: Powerline's spring-loaded clevis, Fas-Nailer's welded-ladder strip, and Spotnails' PEL two-step sear. He credits Spotnails' chief engineer **Bill Beckman** with the fix: a "pop-it" pressure-release valve seen at a 1957 Chicago design show, said to have been developed by Modernair Corporation for fighter-aircraft ejection seats, adapted so a large upper piston holds stored air away from the drive piston until the trigger dumps it into the cylinder. Carlson writes that this "pop-it" principle is still the key to overcoming recoil. This is a good story from one trade historian, not independently corroborated here, and the ejection-seat transfer in particular rests on his account alone. This entry does not call the Spotnails valve "the" breakthrough as fact; it says Carlson does. **Confidence handling.** Paslode's and Max's claims are held at the same discounted confidence this corpus applies to Paslode's company history in [[Air Compressor]] ("world's first" claims not independently verified). Carlson's book was not sourced. Open searches for next time: period patents, advertisements, catalogs and Hughes records before any "first" is ranked. **The combustion architecture, anchored by a primary patent.** **US 4,403,722**, "Combustion gas powered fastener driving tool," inventor Milovan Nikolich, filed January 22, 1981, published/granted September 13, 1983, original assignee Signode Corporation, Illinois Tool Works shown as current assignee in Google Patents (the display is not a legal conclusion on present ownership). It describes one specific arrangement: a piston/driver in a cylinder with a combustion chamber above it, a piezo-electric spark plug, a running fan that purges and mixes, a lifting-rod valve closed by pressing the tool against the work, and a return stroke driven by the thermal vacuum left as gases discharge. It is an early Signode combustion-powered fastener-driving patent and a strong primary anchor for the architecture that Paslode later commercialized. It does not show that every later fuel-cell product practices the same claims or descends from it; link later products or patents only after comparing claims and assignees. Counterpart filings in Canada, the EU and Japan are foreign filings in the same patent family, not evidence of separate inventions. Related Signode/ITW patents (US 4,483,473; 4,483,474; 4,522,162; RE 32,452; 5,197,646; 5,263,439; 6,145,724; 7,341,171) were found by patent-family search only and not read. **Commercial launch (Paslode's own history).** The Paslode Impulse 300/75N, January 1986, is presented there as the first cordless nail gun, for framing with 2–3" nails; the IM-325 followed in 1989 and the first cordless finishing nailer in 1992. These are company-history claims. --- ## ✦ Human side **Traditions & trades — the tool that remade production framing, documented from both sides of the transition.** **Larry Haun** (1931–2011) — already the centerpiece of this corpus's [[Framing Hammer (California Framer)]] entry as the era's most celebrated hand-nailing virtuoso (able to sink a 16d nail in two hammer swings) — is the strongest named crossover figure for the nailer's human story, and his position is genuinely surprising: per secondary sources discussing his book *The Very Efficient Carpenter* (Fine Homebuilding forum thread, "IF LARRY HAUNS SO SMART......", via WebSearch, not independently fetched against the book's primary text — flagged as MEDIUM confidence), Haun argued hammers are, in some respects, better than pneumatic guns, and called pneumatic guns "very dangerous." Haun framed by hand in Nebraska starting 1947, moved to Los Angeles in 1950, and lived the hand-to-power transition firsthand as hand tools were progressively replaced on the crews he worked. A named master carpenter's direct critique of the tool this entry documents is a genuinely valuable, load-bearing human-side anchor — carried at MEDIUM confidence pending independent verification of the book quote against primary text. **The economics, with a controlled study that narrows the jobsite folklore.** Trade sources put raw driving speed at roughly 3:1 (about six hammer nails a minute against about twenty for a dialed-in framing nailer); those figures are retail and trade aggregation, not a measured source, and are carried at low confidence. The better-grounded finding is **Lipscomb et al., "How Much Time Is Safety Worth?"**, a controlled comparison of trigger configurations on pneumatic nailers in residential framing. As the review reports it `[relayed from the reviewer; PubMed page returned no abstract in this pass]`: ten male journeymen each built two prepared shed assemblies; the full-sequential tool added a mean of about 10 minutes, roughly 10% of active nailing time, but only 0.77% of total project time once roughly 1,200 minutes of preparation are counted; and nail count and placement did not differ significantly. The authors concluded the small project-level cost did not justify withholding the safer trigger. "Under 1%" is therefore true only of total project time, not of active firing speed, and the result should not be stretched beyond comparable framing work. The finding is still a useful correction to the belief that contact (bump) firing is necessary for productivity. **Old-timers who hold out, and the skill-loss narrative — real as trade lore, not independently corroborated by a named source this run.** Aggregated accounts (reallifediy.com and similar trade-story pages, via WebSearch, LOW-MEDIUM confidence, no named individual) describe crews and individual framers who deliberately continue hand-nailing — one account names "a family crew in Syracuse that won't use nail guns but are good framers and fast" — and a broader claim that master carpenters once judged one another by the cleanliness of a hand-driven nail, a skill requiring years to build, largely eclipsed once pneumatic tools took over residential framing through the 1970s. Carried here as trade lore, honestly flagged as unnamed and unverified against a primary source, not as settled fact. **Regional/trade variation.** Roofing crews use coil roofing nailers as their own distinct culture (short, wide-head 12-gauge nails, high-volume shingle work). Siding and fencing work are frequently sold and used as one combined tool category — DeWalt markets a single "15° Coil Siding and Fencing Nailer," and Contractor Talk carpenters report using coil siding nailers on fence pickets for years (nailgundepot.com, contractortalk.com, DeWalt product listings — MEDIUM, retailer/forum tier). No source located this run gives a comparably rich account of trim/finish-carpentry nail-gun culture as its own distinct human tradition, beyond the gauge and gun-class distinctions documented under Variations — an honest scope gap. --- ## ✦ Proof of existence - **The single strongest documentary anchor: US Patent 4,403,722, "Combustion gas powered fastener driving tool," read in full text on Google Patents by the original run (not re-read in this pass).** Milovan Nikolich, filed Jan. 22, 1981, granted Sep. 13, 1983, assigned Signode Corp → Illinois Tool Works Inc. (reassignment recorded 1995-04-10). A dated primary record anchoring one combustion-powered fastener-driving design (Signode's); it supports the filing and publication dates, inventor and assignee display, and the described mechanism, and does not show lineage for every later fuel-cell nailer. - **A dated company-history trail, mostly self-history; the ITW ownership point is checked against filings.** Paslode (company self-history): founded 1935 by industrialist J.W. Leslie as a Signode Steel subsidiary (name derived from "Packing Shipping Loading Devices"), ITW acquisition confirmed **1986** (Wikipedia, Paslode UK's own history page, and independently corroborated by the US 4,403,722 patent-assignment record itself, which shows reassignment to Illinois Tool Works). **Ownership correction, checked directly and stated plainly rather than left uncorrected:** a premise that Paslode is currently owned by IDEAL Industries could not be confirmed — ITW's own 2023–2025 SEC 10-K filings (sec.gov/Archives/edgar/data/49826/) and Paslode's current corporate branding both show continued ITW ownership as "ITW Paslode." This entry corrects that premise rather than repeating it, the same myth-correction discipline this corpus applied to Maydole's hammer-founding claim in [[Claw Hammer]]. - **Senco** — founded 1935 by Albert G. Juilfs, Cincinnati, OH; credited (Senco's own company history, independently corroborated by the American Home Furnishings Hall of Fame) with the first fully automatic pneumatic stapling tool, 1949 — the stapler-side sibling lineage to this tool's own nailer development, per Carlson's trade history describing the general path from stapler technology to nailer technology once the recoil problem was solved. - **Bostitch** (Wikipedia-tier) — founded 1896 in Massachusetts by Thomas Briggs as the Boston Wire Stitcher Company, renamed BOSTITCH in 1948, self-described as having progressed "from the wire stitcher to the first coil nailer" (Wikipedia; no specific dated patent or claim for Bostitch's first pneumatic nailer was independently located this run — an honest gap). - **Hitachi Koki / Metabo HPT** — traces to Nippei Shokai (1918); Hitachi Koki formally founded 1948; renamed Koki Holdings/HiKOKI/Metabo HPT in 2018 following a KKR acquisition of Hitachi's power-tool division (company self-history, metabo-hpt.com — not independently corroborated against a third-party source this run). - **Max Co., Ltd.** — Japan, originated as Yamada Air Industry, becoming Max Co. in the 1950s; states its T2-A was "Japan's first air nailer," 1962 (a staple-driving tool by its own account), dated the same year as Paslode's GN-212 claim (Max's own company history: a narrower claim, not evidence of independent invention of the GN-212's class; see History). - **A genuine, honestly-reported museum gap.** No museum or trade-collection accession record for a pneumatic or cordless nailer — Paslode, Senco, Bostitch, or otherwise — was located this run, despite direct search attempts. This is stated as a **search-tool access limitation, not a confirmed institutional absence** — a live query directly against `collections.si.edu` (rather than via general web search) was not achieved this run and is recommended as a specific next step, the same distinction this corpus's [[Staple Gun]] entry already draws for its own unconfirmed Smithsonian gap. - **Earlier and adjacent patents, identified but not independently read in full text this run (an honest sourcing-tier gap, named per item):** the 1862 Doig bulk-nailing-machine patent (not located); **US 3,542,273** (Granville R. Hedrick, granted 1970 — a compressed-air nail-driving device for wood flooring, operable by either external mallet blow or trigger, a genuine transitional hammer-actuated/trigger-actuated design); **US 4,194,664** (Siegmann — pneumatic nailer/stapler with an inlet-valve-fed piston); **US 4,907,730** (Jean-Paul Dion, 1990 — a "feeler disc" contact-trip safety-interlock patent, relevant to the actuation distinction); **US 6,443,348 B2** (palm nailer with rotating magazine, provisional filed Dec. 9, 1999). --- ## References Retained sources, with exact links (from the reviewer's Source Notes; "read" means read in this fix pass, "relayed" means the reviewer's description or the original run's reading, not re-read): | Source | Link and date | Used for | Status | |---|---|---|---| | OSHA/NIOSH, *Nail Gun Safety: A Guide for Construction Contractors* (NIOSH 2011-202 / OSHA 3459) | [cdc.gov PDF](https://www.cdc.gov/niosh/docs/2011-202/pdfs/2011-202.pdf), 2011 | Safety sequence, 12-inch hand rule, clamps, disconnection, line of fire, PPE, medical care | read | | OSHA, "Nail Gun Safety" | [osha.gov](https://www.osha.gov/nail-gun-safety) | Hospitalization claim, twofold contact-trigger risk, 2 of 5 apprentices | read | | NIOSH, "First NIOSH Comic Helps Dispel Internet 'Myth'" | [cdc.gov](https://www.cdc.gov/niosh/bulletin/2013/nail-gun-comic.html), 2013 | Measured pneumatic velocities; the 1,400 ft/s confusion | read | | NIOSH, "NIOSH, Nail Guns, and Consensus Standards: Where We Stand" | [cdc.gov](https://www.cdc.gov/niosh/bulletin/2015/nail-guns.html), 2015 | Full-sequential recommendation; critique of 2015 standard | relayed | | Lipscomb et al., "How Much Time Is Safety Worth?" | [PubMed 18763410](https://pubmed.ncbi.nlm.nih.gov/18763410/); [CDC full text](https://stacks.cdc.gov/view/cdc/193575/cdc_193575_DS1.pdf), 2008 | Ten-journeyman, two-shed trigger comparison | relayed (PubMed page returned no abstract) | | CPWR/eLCOSH, "Nail Guns: Injuries, Productivity and Recommendations" | [elcosh.org](https://elcosh.org/document/2066/d001056/nail-guns%3A-injuries%2C-productivity-and-recommendations.html) | Double-fire explanation, injury proportions; an institutional synthesis, not a substitute for the underlying papers | relayed (original run) | | Paslode Cordless XP 30° Framing Nailer operating manual | [paslode.com PDF](https://www.paslode.com/getmedia/a5e4795f-6db6-4255-842f-9d40dbc33fdc/Cordless-XP-30-Degree-Framing-Nailer-Operating-Manual.pdf) | Fuel-cell ventilation, carbon monoxide, storage limits, model jam procedure | manual, relayed | | Makita XNB03 cordless framing nailer manual | [makitatools.com PDF](https://cdn.makitatools.com/apps/cms/doc/prod/XNB/d5edeb55-dc22-40d8-9251-71d5a7bb7917_XNB03_IM_885A75-941.pdf) | Mode selection, pre-use safety-system test, battery removal | manual, relayed | | Makita Canada, DBN900ZK product page | [makita.ca](https://www.makita.ca/index2new.php?catid=&event=tool&id=4099) | Air-spring drive, distinguished from gas and flywheel models | relayed | | DeWalt, "How does the DCN690 Cordless Nailer work if it doesn't use gas?" | [dewalt support](https://support.dewalt.com/hc/en-ae/articles/360016780678-How-does-the-DCN690-Cordless-Nailer-work-if-it-doesn-t-use-gas) | Flywheel drive | relayed | | US 4,403,722, "Combustion gas powered fastener driving tool" (Nikolich; filed 1981-01-22, published 1983-09-13) | [Google Patents](https://patents.google.com/patent/US4403722A/en) | One combustion design; not lineage for every later model | read by original run | | Don Carlson, "A Brief History of Portable Nail Guns," *Journal of Light Construction* | [jlconline.com](https://www.jlconline.com/tools/fastening-tools/a-brief-history-of-portable-nail-guns_s/), 2018-12-14 | Attributed trade history (trade-history source, not independent proof of any "first") | relayed | | Paslode UK, "40 Years of Innovation" | [paslode.co.uk](https://paslode.co.uk/40-years-of-innovation-the-history-of-paslode/) | Paslode's own 1959 and 1962 claims | relayed | | MAX, product history | [max-ltd.co.jp](https://www.max-ltd.co.jp/en/about/company/steps/manufacturing.html) | T2-A, 1962, Japan's first air nailer, staple-driving | relayed | | WoodWorks, "Using Gun Nails in Wood-Framed Shear Walls and Diaphragms" | [woodworks.org](https://www.woodworks.org/resources/using-gun-nails-in-wood-framed-shear-walls-and-diaphragms/) | Fastener specification, evaluation reports | relayed | | APA, "Effect of Overdriven Fasteners on Shear Capacity," TT-012 | [apawood.org](https://www.apawood.org/guides-tools-training/technical-document-library/technical-topics/effect-of-overdriven-fasteners-on-shear-capacity/) | Conditional assessment and corrective-fastening guidance | page read as summary only; criteria in the PDF not read | | Judd and Fonseca, "Capacity of Oriented Strand Board Shear Walls with Overdriven Sheathing Nails," *J. Struct. Eng.* 2002 | [ASCE](https://ascelibrary.org/doi/10.1061/%28ASCE%290733-9445%282002%29128%3A7%28898%29) | Specimen-specific strength and displacement changes | relayed (fetch failed) | | ANSI approved-standards list; ISANTA notice | [ANSI list](https://share.ansi.org/Shared%20Documents/Standards%20Activities/American%20National%20Standards/Approved%20and%20Proposed%20ANS%20Lists/Approved%20ANS.pdf); [ISANTA](https://isanta.org/news/ansi-isanta-snt-101-2024-edition-of-standard-in-effect) | ANSI/ISANTA SNT-101-2024 revised the 2015 edition; requirements not reviewed | relayed | | Lipscomb, "Nail gun injuries treated in U.S. emergency departments, 2006–2011," *Am. J. Ind. Med.* 2015 | no link confirmed | Injury estimates and period | relayed | | Clinical review "Nail Gun Injuries," litfl.com (Guthrie and Cadogan), citing Pierpont 2008, Horne and Corley 2007, Hoffman et al. 1997 | no link confirmed | Body-location proportions | relayed (original run) | | US 3,542,273 (Hedrick, 1970); US 4,194,664 (Siegmann); US 4,907,730 (Dion, 1990); US 6,443,348 B2 (palm nailer) | Google Patents, no link confirmed | Adjacent patents | bibliographic only, not read | | Senco, Bostitch, Metabo HPT/Hitachi, Max company histories; ITW SEC 10-K filings FY2023–2025 | no link confirmed | Company self-history; ITW ownership of Paslode | self-history, relayed | **Research notes, unverified leads (not load-bearing).** Larry Haun's stated views on nail guns (secondary discussion of *The Very Efficient Carpenter* and a forum thread; the book was not read). Trade-lore about old-timers and hand-nailing crews (unnamed aggregators). Nailer-versus-hammer speed ratio (retail aggregation). Ryobi dry-fire lockout (forum-tier). Roofing/framing nailer confusion threads (Fine Homebuilding, Garage Journal, finepowertools.com). The CPWR videos "Death in the Sierra" and "Just Driving Down the Street." The 1862 Doig patent was never located. A Smithsonian collections query was not made; the missing museum record is a search-access limitation, not a confirmed absence. Next sources to retrieve: period patents and catalogs for the early "firsts," each model manual for the schema fields above, and APA TT-012's PDF. --- ## Forge image specs (for ticket) 1. A labeled cutaway comparing the three power architectures side by side: pneumatic (compressor + hose + valve-fed piston), combustion/fuel-cell cordless (spark plug, combustion chamber, purge fan, fuel cell), and battery-only cordless (labelled by its model-specific drive, for example flywheel or air-spring, not as one mechanism) — same driver-blade/nose assembly, different ways of storing and releasing the drive energy. 2. A side-by-side diagram of sequential-trigger vs. contact/bump-trigger firing sequences, showing exactly where the double-fire risk enters the contact-trigger cycle — this is the tool's single most safety-consequential mechanical fact and deserves its own clear visual. 3. A magazine-format comparison: coil (wound strip, indexing feed, ~200–300 nails) vs. stick/strip (angled collation, 20–40 nails per stick) — paired with a visual of why a coil roofing nailer and a coil framing nailer look alike but cannot substitute for each other (nail length/head size mismatch). --- ## The reviewer's corrections (12) - `BLOCKER` — 1. Remove the instruction to hold material with the free hand — Exact claim: One-handed operation is “arguably the tool's real mechanical advantage,” because it frees “the off-hand to position and hold material”; the matching block repeats “one-handed fastening while the off-hand positions material.” - `BLOCKER` — 2. Add the minimum operational safety sequence and architecture-specific isolation — Exact claim: “How to use it well” consists mainly of matching the fastener, checking depth, and using full-sequential actuation; the dangerous section is dominated by injury statistics and anecdotes. - `BLOCKER` — 3. Delete the 1,400 ft/s pneumatic/cordless nailer comparison — Exact claim: “Nail guns can produce fastener velocities up to roughly 1,400 ft/s; skin penetration occurs around 150 ft/s and bone fracture around 195 ft/s — meaning the tool operates at seven to nine times the energy threshold needed to cause serious injury.” - `BLOCKER` — 4. Correct the overdriven-fastener figures and remove the unsupported “industry-standard habit” claim — Exact claim: Nails overdriven 1.6/3.2/4.8 mm caused “9%, 13%, and 22% loss of joint load capacity,” and nail guns are “commonly adjusted and calibrated to run slightly overdriven, specifically to avoid the labor cost” of setting proud nails by hand. - `SHOULD-FIX` — 5. Split battery-only mechanisms instead of calling them “spring/flywheel” — Exact claim: “Battery-only spring/flywheel-driven design” is one of three architectures, and Makita's DBN900ZK is used as the example of a brushless motor compressing an “air-spring mechanism.” - `SHOULD-FIX` — 6. Narrow and correctly report the trigger-productivity study — Exact claim: “The riskier contact-trip (bump-fire) trigger produced no significant productivity advantage — under 1%,” and full-sequential use has “no meaningful speed cost.” - `SHOULD-FIX` — 7. Rebuild origin history without treating self-history and one trade account as resolved priority — Exact claim: Pynoos's 1944 tool is “the first pneumatic nailer,” Burnison's 1951–52 tool is the first commercially successful jobsite nailer, Paslode and Max represent “parallel invention,” and the Spotnails valve is “the actual breakthrough.” - `SHOULD-FIX` — 8. Bound the combustion patent claim — Exact claim: US 4,403,722 is “the direct mechanical ancestor of every fuel-cell ‘Impulse’-type nailer sold since” and establishes “the exact mechanism underlying every fuel-cell cordless nailer.” - `SHOULD-FIX` — 9. Correct fastener and variant matching — Exact claim: Framing nailers use “10–16 gauge / ‘16d-class’ nails”; roofing nailers are “12-gauge” with “~1¾ inch depth”; the manufacturer's fastener line must match “gauge, crown, length, and collation angle”; roofing nailers are for shingles/underlayment “only”; and finish nails are categorically … - `SHOULD-FIX` — 10. Replace broad substitution and “nothing displaces it” claims with conditional routing — Exact claim: A nailer substitutes “directly and almost completely” for a hand hammer in volume framing; a hand hammer is required where an inspector or connector specification calls for “hand-nailing accuracy”; and “nothing” displaces the nailer in its job. - `SHOULD-FIX` — 11. Recalibrate injury and medical claims — Exact claim: The tool is “by a wide margin, the most injury-documented hand power tool in residential construction,” and the section treats older annual emergency-department estimates, clinical percentages, and a plaintiff-law-firm story as one high-confidence block. - `MINOR` — 12. Make references auditable and remove run-process residue — Exact claim: The references table lists titles and sites without clickable URLs, while the entry repeatedly says “directly fetched,” “via WebSearch,” “not independently fetched this run,” “the strongest single,” and “the richest... this corpus has yet built.”