# Jeweller's Saw (Piercing Saw)

Hewn Tool Library · https://hewn.build/tools/jeweller-s-saw-piercing-saw

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: "Jeweller's Saw (Piercing Saw)." Hewn Tool Library, hewn.build/tools/jeweller-s-saw-piercing-saw. Reviewed 2026-07-29.

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## Identity
- **Name:** Jeweller's saw, also called a piercing saw (the two names are used interchangeably for the same tool across every source found this run — "piercing" describes the tool's signature technique, "jeweller's" its trade). Not to be confused with the corpus's own [[Razor Saw]] — see Lineage-misuse, below, for the two-way confusion the corpus's own prior tree note had merged them under.
- **Family/category:** Frame saw — Saw Family branch ② (frame-tension), the branch that already holds the [[Coping Saw]] and [[Fretsaw]]. A manufacturer's own technical literature states this plainly: "Fret saws and jeweler's saws are the same tool by different names... The blades are the same length, but their designs are different" (Knew Concepts, "The Way of the Saw," fetched full text). That is one manufacturer's taxonomy, not necessarily universal trade language. This entry therefore separates three layers: (1) the frame, an unpinned 5-1/8-inch-class fret/jeweller frame (the coping saw stays separate, because it uses a longer pinned blade); (2) the blade configuration loaded in it (fine metal-cutting jeweller's, ordinary woodworking fret or skip-tooth, marquetry, or spiral where the exact frame permits) `[manual, relayed]`; and (3) the trade or use name. The corpus keeps this separate entry for the jeweller's configuration, and the boundary with [[Fretsaw]] is the loaded blade and the work, not a different frame.
- **One-line:** A small, hand-held, tensioned frame saw with an interchangeable, disposable, extremely fine blade — thinner and finer than its coping-saw and fretsaw cousins — built to pierce interior cutouts through a pre-drilled starter hole and to turn tight corners on its shallow-spined blade, at the cost of fragile blades that break readily.

## How NOT to use it (the heaviest section)

**Not-for:** a pitch that breaks the Rule of Three — fewer than three teeth engaged in the material's thickness at once causes the blade to jump forward into the gullet between teeth and slam into the next one, which "usually breaks the blade, or certainly causes it to stop dead" (Knew Concepts, "The Way of the Saw," fetched full text — the manufacturer's own stated design limit, not an inferred one). The rule sets a minimum work thickness for a given tooth pitch; it is not a maximum. Per the reviewer's reading of the same guide, Knew Concepts applies it from thin gold sheet to a pine 2×4, and says thicker work cuts slowly `[manual, relayed]`. Thin sheet therefore needs a finer pitch, and thick or hard stock needs a coarser one or a different tool. Any job needing a rigid, controlled straight cut is better served by this corpus's [[Razor Saw]] or a backsaw, a structurally different tool (see Lineage-misuse).

**Dangerous:** lower-energy than a powered saw, not harmless. The absence of a located injury narrative is a research result, not evidence that the tool is safe. The hazards and controls below are the documented ones.
- **Eyes.** Wear safety glasses. The Rio Grande / Knew Concepts Precision Saw Guide (read in this fix pass) says: "During sawing, for instance, a saw blade can break and lodge in an unprotected eye," and that safety glasses should be worn at all times during metalsmithing activities. Ganoksin's "Rules for Tools" (read in this fix pass) likewise says to use eye protection in case the blade snaps and a piece flies into the eyes.
- **Hands and body out of the blade path.** Ganoksin warns against placing your fingers in the path of a saw blade, since "if the blade breaks it can plunge into your finger," and says to cut away from yourself (given there as general hand-tool advice). Support the work at the bench pin or a fixture without placing the supporting hand beneath the stroke, and use a fixture for work too small, sharp, awkward or unstable to hold safely `[manual, relayed]`.
- **Inspect before sawing.** Check the blade for kinks, rust, cracks, missing teeth and heat damage; check clamps and frame alignment; seat both blade ends fully; and release or reset tension as the exact manual directs `[manual, relayed]`.
- **Stored energy.** A tensioned fine blade is stored energy. Use long, controlled strokes and light pressure, and stop rather than forcing a stalled, wandering or twisted blade `[manual, relayed]`.
- **Broken blades and swarf.** Control and dispose of broken blade fragments and sharp swarf safely. Do not brush them toward skin or blow metal or hazardous dust across the bench. Deburr or otherwise control the sharp edges of the work after cutting `[manual, relayed]`.
- **Bystanders.** Keep bystanders clear of the work area `[manual, relayed]`.
- **Powered version.** The Knew Concepts New Concept Saw manual (read in this fix pass) says the blade "has very little power to hurt the operator if it breaks." That is a statement about that machine's cable-loop design, not about hand saws.

**Starter-hole drilling is its own operation.** Interior piercing needs a drilled hole first, and drilling has its own hazards that this tool's controls do not cover. Follow the drill or drill-press manual; secure the small workpiece with an appropriate fixture; use the correct bit and backing or support; keep hands clear; and control breakthrough `[manual, relayed]`. (The Precision Saw Guide, read here, also advises drilling a hole at every inside corner, because a drilled corner is less likely to crack than a sharp one.)

**Material exposure.** Identify the work material and any coatings first. Cutting metal, nickel silver, plastics, wood, plaster, or old or unknown stock can create sharp swarf or hazardous dust; lead, cadmium, nickel, coatings and some plastics need a material-specific assessment. Follow the material's SDS and site controls for dust, swarf, skin contact, ventilation, cleanup and disposal, and the product label for any lubricant `[manual, relayed]`.

**Damaging:** ★ **over-tightening a blade clamp at its friction points snaps the blade before a cut is even made** — a directly-sourced, unusually strong finding: Mark Maxwell, a 25-year professional goldsmith, broke blades this way on a new saw design (Ganoksin/MJSA Journal, fetched full text), and the manufacturer's own reply in the same published piece confirms it changed its machining process in direct response. A second, independently corroborated damaging pattern, converging across three separately-fetched sources (Cooksongold, Dave Cushman, Interweave): a clear "ping" or "sing" when the blade is flicked is useful maker-supported qualitative guidance for tension, but it is not a calibrated tension and not a universal setting: follow the exact frame's instructions, and do not transfer hand-frame tension to a powered saw (its manual calls for lighter tension). Over-tightening the clamp and over-tensioning the blade are different failure modes, and a blade that is too loose or too tight can break either way; forcing or pushing the blade rather than letting the teeth do the work is named directly by Interweave as "one great way to break the blade"; and twisting the blade sideways while turning a corner — rather than pivoting the workpiece — is independently named by both Cooksongold and Cushman as the single most common way a blade breaks mid-cut.

**Beginner-trap:** ★ **installing the blade backwards — teeth facing away from the handle instead of toward it.** Sourced independently by two fetched pages that agree on both the fact and the mechanism: Cooksongold's how-to guide states the teeth must face "downwards... towards the handle," and Dave Cushman explains why in mechanical terms: cutting on the pull stroke "held the blade straight by the extra tension due to teeth resistance rather than buckling as it would tend to do on a push stroke." A backwards-installed blade will still cut something — badly, and often long enough for the mistake to go unnoticed before the blade snaps. A second, independently sourced beginner-trap: choosing a blade gauge too fine for the material's actual thickness, which stalls the cut and invites exactly the extra forcing pressure that then breaks the blade (Interweave, fetched) — the same failure loop as the damaging-misuse mechanism above, caught earlier, in the choice of blade rather than the stroke.

**Lineage-misuse:** ★ **expecting this tool to survive a razor-saw-scale job, or expecting a razor saw to pierce a curve — the two-way version of a confusion this corpus's own [[Razor Saw]] entry already documents from the other side.** Named poster **TheRhino** (DakkaDakka, 2010, fetched full text in the Razor Saw entry's own research, cited again here as it concerns this tool directly): *"I blew up four of them cutting a single piece of drainage pipe... I gave up and ended up using my Ryobi jigsaw instead."* A maker expecting this tool's fine, curve-capable blade to also deliver a rigid backsaw's bulk-cutting toughness destroyed four blades before abandoning the approach — the mirror-image error (expecting a razor saw's rigid spine to pierce or curve-cut the way this tool does) is structurally impossible for the razor saw, not just harder, per the same corpus's Razor Saw entry. **A second, independently sourced lineage-misuse case, this time against this tool's own mechanical siblings rather than the razor saw:** the "marching in place" cornering technique that works on this tool's shallow-spined blade is explicitly documented by Knew Concepts as *not* transferring to the deeper-spined fret and coping-saw blades in this same corpus's [[Fretsaw]] and [[Coping Saw]] entries — a maker who has learned to pivot tight corners on a jeweller's blade and tries the identical technique on a fret blade is fighting a spine that won't cooperate the same way. Two distinct lineage-misuse pairs (vs. the razor saw, vs. its own frame-saw siblings) anchored to two independent, directly-fetched sources.

## Correct use
**Genuinely good at:** piercing interior cutouts through a pre-drilled starter hole (the tool's signature technique: its fine unpinned blade excels at small, intricate interior piercing through a starter hole. Fret saws and some coping saws can also make interior cuts, with different blade width, kerf, radius, finish and material suitability); tight-radius curves and fine detail in thin sheet metal; jewelry bezel shaping; fine marquetry/inlay patterns in veneer or thin plywood; wax, acrylic, and plaster pattern-cutting for casting; working as an improvised fine "file" in interior spaces too small for another tool to reach — a sourced practitioner technique, not a general substitute for a file (Ganoksin's "Basic Sawing Techniques," fetched).

**Short version of using it well:** brace work on a [[Bench Pin (Bench Peg)|bench pin]] or V-shaped birdsmouth board so the blade clears the support; install the blade teeth-down, facing the handle, so the cut happens on the pull (down) stroke — this keeps the thin blade in tension rather than letting it buckle under a push, the identical mechanical logic already documented in this corpus's [[Razor Saw]] entry, here running in the opposite direction because this blade has no rigid back to fall back on if the direction is wrong (model-specific instructions control, and specialised guides or fixtures can orient the blade differently); use the full length of the blade in a slow, steady rhythm rather than short choppy strokes; on a corner, stop advancing and "march in place" — keep sawing while slowly pivoting the workpiece up to 45° — a technique the Knew Concepts technical literature explicitly notes does *not* transfer to the thicker-spined fret/coping blades (see Lineage-misuse); for any work thickness, choose a pitch that keeps at least three teeth engaged in the material (the "Rule of Three" — too few teeth and the blade can jump the gullet and break); lubricate the blade with beeswax or a proprietary product to cut friction and clogging.

## Matching (the workbench's first read)
- **Does:** pierces interior cutouts in thin sheet metal from a pre-drilled starter hole; cuts intricate curved profiles and tight-radius turns in thin flat stock; shapes and trims jewellery bezels and small metal components; cuts fine marquetry/inlay patterns in veneer or thin plywood; cuts jeweller's wax, acrylic, and plaster casting patterns; serves as an improvised fine file in tight interior spaces.
- **Suits:** jewelry-making and silversmithing (primary trade), fine marquetry/inlay woodworking, model-making (wax/plastic casting patterns), small pierced-metal decorative work. Not general woodworking joinery, and not a first choice for a cut requiring a rigid dead-straight line. Thick or hard stock is a blade-, frame- and material-specific question, not a blanket exclusion (see Not-for).
- **Kit-fit:** pairs with a [[Bench Pin (Bench Peg)|bench pin]] or V-board/birdsmouth board (bracing), a drill for starter piercing holes (the blade-gauge table below gives the matching drill bit size per blade size; the drilling is a separate powered or manual operation with its own controls, see Dangerous), files for post-cut cleanup, and beeswax or a lubricant stick for the blade. Substitutes coarser: the corpus's own [[Coping Saw]] can step in for less delicate interior cuts where breakage risk matters more than fine detail (Knew Concepts' examples run about 18 TPI for a coping blade against roughly 28–92 TPI for the listed jeweller's blades, so substantially coarser than common fine jeweller's blades). Is substituted, for deeper-throat/coarser marquetry work, by the corpus's own [[Fretsaw]]. No powered equivalent is named here: the Knew Concepts powered saw is a documented relative whose current availability, exact model, blade limits, guarding and manual are unsettled, so it is not offered as the production-scale substitute. **Cannot replace:** the corpus's [[Razor Saw]] or any backsaw on a job needing a straight, rigid, controlled cut — this tool's whole mechanical identity (an unbacked, tensioned, curve-capable blade) is the opposite design answer to that job.
- **Not-for (project-keyed):** a project calling for a rigid, dead-straight cut (straight cuts are possible but harder to track with shallow-spined fine blades; a [[Razor Saw]] or backsaw usually fits better); general carpentry or furniture joinery. Thick or hard stock is not a universal exclusion: ⅛"–3/16" is not a maximum. Thick work may be slow, hard to clear, or outside a given blade or frame maker's recommendation, so state suitability by blade, material, frame, cut quality and maker guidance rather than by a fixed ceiling.
- **Access:** genuinely low-friction to start, but with a real, well-documented early learning cost — fine jeweller's blades break readily, especially during learning, and a beginner should expect to go through blades while the feel develops. Repeated or location-consistent breaks are a signal, not a rite of passage: diagnose blade choice, installation direction, alignment, clamp condition, tension, lubrication, pressure, work support and turning technique (see Beginner-trap, below, for the specific mechanisms).
- **Revival:** a genuinely live, not heritage-only, practice. Jewelry-making and metalsmithing retailers (Rio Grande, Otto Frei, Contenti, Cooksongold, H.S. Walsh, Eternal Tools, Pepe Tools) all currently and actively sell this tool and its consumable blades, and Ganoksin — describing itself as "the world's largest educational website for jewelry making and metalsmithing" — hosts an active current community forum. This is a working trade tool in continuous, current production and use, not a museum piece being revived.

**Blade-gauge / material-thickness table** (Knew Concepts, "The Way of the Saw," fetched full text — sourced to their own supplier data, noted by the manufacturer as representative but not exact across every brand):

| Blade | Thickness | TPI | Min. material (B&S gauge) | Drill for piercing |
|---|---|---|---|---|
| 8 (coarsest commonly used; sizes above #8 are uncommon) | .0197" | 28.0 | 12 | #55 |
| 4 | .0150" | 38.0 | 16–18 | #67 |
| 1/0 | .0110" | 53.5 | 18–22 | #73 |
| 4/0 | .0086" | 66.0 | 22 | #77 |
| 8/0 | .0063" | 89.0 | 26 | #80 |
| 10/0 (finest) | .0055" | 92.0 | 26+ | #80 |

*(Drill equivalence and actual clearance vary with blade and hole quality; the table is tied to the named blade-maker data. Full 17-row table available in the source PDF; abridged here to the practically-used range. The manufacturer's own document notes the theoretical scale runs to #18 but blades above #8 are "uncommon," and "most jewelers use a range from #2 down to 6/0." Wikipedia's own listing, by contrast, names only 8/0 through 6 — a narrower, possibly dated or regionally different naming convention; flagged as a discrepancy, not resolved, with the manufacturer-direct source treated as the stronger citation.)*

## Anatomy
- **Frame** — the C-shaped rigid body that holds the blade under tension and gives the tool its throat depth (50–200mm / 2–7.9" across the category, per Wikipedia's Piercing Saw entry, fetched). Modern premium frames (Knew Concepts) are aluminum, cut with truss-like openings for rigidity without added weight (US8,347,513B2, fetched); budget and mid-tier frames (Grobet's "Swiss-style") are also commonly aluminum, contradicting a simple "cheap = steel, premium = aluminum" assumption — both material choices appear across price tiers, and this entry does not oversimplify that split.
- **Tensioning mechanism** — two families exist in current products: **screw-tension** (a knurled nut tightens the frame directly) and **cam-lever tension** (a lever delivers faster tension/release, and on premium models is rated at meaningfully higher blade tension than screw designs, per current retailer listings — exact PSI figures held at lower, snippet-level confidence). Tension is model-specific: follow the exact frame's loading and tensioning instructions, and do not use clamp-screw force to compensate for dirty or misaligned clamps (clamp force and blade tension are different things) `[manual, relayed]`.
- **Blade clamps** — thumbscrews or, on premium frames, swivelling clamps ("ASD," released via cam lever). On the referenced Knew Concepts model the spring-loaded clamps snap into locking positions at 0° (straight forward) and 45° to either side; the instruction sheet states the clamps cannot rotate 360°. Other models must be described from their own instructions.
- **The blade itself** — gullet (the gap between teeth), tooth, and spine (the un-toothed back edge). The defining anatomical fact of this branch's jeweller's-grade blades: an unusually shallow spine relative to a coping or fret blade, which is what lets the blade pivot 90° within its own kerf — and one reason fine jeweller's blades are fragile consumables that break readily. ("Spine" here is the untoothed portion behind the gullets; "unbacked" is the clearer word when contrasting the frame saw with a backsaw.)
- **Handle** — ergonomic grip at the frame's base; manufacturer copy for at least one current line (Grobet) specifically credits handle design with reducing hand fatigue over long sawing sessions (retailer-sourced, lower confidence).

## Variations (living)
| Variant | What differs | What it's for |
|---|---|---|
| Fixed-throat frame | Frame length is set; broken blade stubs below the fixed length can't be re-tensioned | Standard use where full-length blades are routinely available |
| Adjustable-throat frame | Frame telescopes to shorter lengths | Some adjustable frames permit an undamaged shorter blade remnant to be reclamped if the manufacturer allows it and both ends engage fully (Wikipedia, Piercing Saw, fetched: "the frame is adjustable for blade length to allow the re-use of broken pieces"). Fixed-length frames may reject short blades: the Knew Concepts Mk.III instructions say shorter blades will not work `[manual, relayed]`. Discard kinked, cracked, overheated, corroded or otherwise damaged remnants. |
| Jeweller's/piercing blade (plain) | Shallow spine, ~1:2 thickness-to-width ratio, pivots 90° within its own kerf | The default for thin metal — gold, silver, brass, copper |
| Ordinary fret / woodworking blade | Deeper spine, ~1:3 ratio, coarser teeth, tracks straighter but turns corners less readily | Woodworking and fret work — the corpus's own [[Fretsaw]] territory (the [[Coping Saw]] uses a longer pinned blade and stays a separate system) |
| Marquetry blade | Per the reviewer's reading of Knew Concepts, resembles a jeweller's blade with coarse teeth and a similarly shallow spine; exact geometry not restated here `[manual, relayed]` | Marquetry cutting; consult the maker's geometry and material guidance for the specific blade |
| Skip-tooth blade | Every other tooth omitted, widening the gap for faster waste clearance | Wax, acrylic, wood — material that clogs a standard-pitch blade |
| Spiral blade | Teeth cut in every direction around the blade's circumference | Fastest cutting in any direction without rotating the workpiece (wax, plastic, plaster, soft wood); leaves a rougher edge than a plain blade |
| Knew Concepts powered saw ("New Concept Saw") | Bench-mounted, motorized, 120 strokes/min maximum per its manual, cable-and-blade continuous loop, lighter blade tension than a hand saw; current availability not established | A documented powered relative; check the exact model and current manual before relying on it |

## Trades (where it appears)
Jewelry-making and silversmithing — the tool's home trade and the source of most of this entry's technique sourcing. Fine marquetry and inlay woodworking — the same mechanism, a coarser sibling blade, already documented in this corpus's [[Fretsaw]] and [[Coping Saw]] entries. Model-making — wax and plastic pattern-cutting for lost-wax casting. Dentistry/dental mechanics — a genuine, named cross-trade instance (Dave Cushman's tutor, "a dental mechanic of considerable ability," see Human Side) though not established here as a routine trade use, only a documented single case. Watchmaking — claimed as a historical connection by a named forum poster (Zaruba) but not independently corroborated by any other source found this run; reported at that lower confidence, not as settled fact.

## Lineage
**Ancestors / kin.** Mechanically a direct sibling of the already-built [[Coping Saw]] and [[Fretsaw]] — same tensioned, unbacked (no rigid back), C-frame-and-blade-clamp architecture, descended from the same medieval-to-early-modern frame-saw root those entries already document. What distinguishes this branch member is blade geometry: jeweller's blades run roughly a 1:2 thickness-to-width ratio versus ordinary fret blades' roughly 1:3 (marquetry blades are a separate case: per the reviewer's reading of Knew Concepts they resemble jeweller's blades with coarser teeth and similarly shallow spines `[manual, relayed]`), and jeweller's blades pivot within their own kerf enough to turn a full 90° without advancing, depending on blade size, material, tension and technique — a maneuverability the deeper-spined ordinary fret and coping blades do not match (Knew Concepts, "The Way of the Saw," fetched full text).

**Contemporaries — the false cousin.** The corpus's own [[Razor Saw]] entry (built Run 287) already documents this from the other side: the two tools share a "small, fine precision saw" market niche and get casually conflated, but the razor saw is a rigid-spine **backsaw** (straight cuts only) while this tool is an unbacked **tensioned frame saw** (can pierce and cut curves). Treated as a related-but-mechanically-distinct tool, not a variant — see Lineage-misuse below for the sourced case of makers confusing the two in practice.

**Powered relative, current availability not established.** Knew Concepts documented a bench-mounted powered saw that takes jeweller's-saw blades, described in its "New Concept Saw" instructions (read in this fix pass): the maximum motor speed is set at 120 strokes per minute, because higher speed prematurely wears and overheats the blade (the overheating reason is the reviewer's relay `[manual, relayed]`), and the manual advises lighter blade tension than on a hand saw. The manual describes the cable and blade as one continuous loop and says the blade "has very little power to hurt the operator if it breaks." It does not describe an electronic cutout that stops the saw instantly, and this entry no longer claims one. The reviewer found a sold-out Otto Frei listing and no current Knew Concepts shop listing, which shows a product record, not a living product line `[manual, relayed]`. It is therefore not called a current descendant here. It is distinct from the corpus's general-purpose [[Scroll Saw]] entry.

## History (Petroski lens — what failure did each evolution fix?)
**Deep origin — real, but honestly unresolved.** A 2003 Ganoksin Orchid forum thread ("Jeweler's Saw History," fetched full text) is this corpus's best window into how the jewelry trade itself talks about the tool's age, and it is refreshingly honest about not knowing. **Doug Zaruba** proposes the saw was "invented (in Europe) during the Renaissance," reasoning that jewelers already had the fine hand-cutting skill needed for clockwork gear teeth, and that a saw blade is functionally "a series of chisels in a row" — a real technical insight, though offered as informed speculation, not documented fact. Zaruba backs the claim with a private collector's item: a saw frame stamped "Morris," English-made, which he dates to "around the early 1600s" by his own assessment — thumbscrew-tensioned, non-adjustable, 3" blade. **Niels Løvschal** independently pushes the underlying drawbench/wire-drawing technology (needed to make fine blade stock at all) back further still, to Viking-era archaeological drawplates. No poster in the thread claims certainty, and this entry doesn't either — the Morris saw is a named private collector's dated object, not a museum accession, and is reported at that confidence level.

**A documented illustration anchors the frame-saw family's origin more solidly than the jeweller's-specific thread does.** Christopher Schwarz's "A History of Coping Saws in Five Paragraphs" (Lost Art Press, fetched full text) — written about the family's wood-cutting side but explicitly treating jeweller's and coping/fret saws as siblings — cites **André Félibien's 1676 published drawing** of a "petite scie de marqueterie," teeth pointing away from the handle, as a dated illustration of a marquetry saw (not the earliest image of a frame saw; see the evidence ladder under Proof of existence). The same page's comment thread (fetched) adds an even earlier ancestor: a metal-framed saw in the **Mästermyr chest** (an 11th-century Viking tool hoard) — though that blade was simply riveted with no tensioning mechanism, meaning it lacks the defining feature (tension) that makes a jeweller's saw what it is, and is better read as an ancestor of the *idea* of a frame saw than of this tool specifically.

**What the tensioning mechanism itself evolved to fix.** A directly-read 1888 US patent (**US390996A, Cornelius Tenney, "Saw-Frame"**) states its own problem plainly: ordinary saw frames "bend or bulge laterally... so that the tension device cannot be tightened up to its fullest capacity" — Tenney's fix was a concealed metal brace preventing that bulge. This patent covers the general buck-saw/frame-saw family rather than the jeweller's saw by name, but it is a clear primary-source statement of a frame-rigidity problem that tensioned-blade saws face: a thin, unsupported blade needs a frame that can hold real tension without deforming, or the blade won't stay straight. It is a general saw-frame patent, not proof of jeweller's-saw development. **A secondhand-only claim, flagged rather than trusted:** a blog (Progress Is Fine, fetched) cites an 1883 US patent application by "William Jones" for a "saw frame for a jeweler's saw" as the first patent matching this description by name — neither research leg could independently retrieve the primary patent document or confirm a patent number, so this is reported as an unverified secondary citation, not fact.

**The modern mechanism's own patent, directly verified.** **US8,347,513 B2, "Hand-held saw with rigid frame," inventor Buster Lee Marshall** (Knew Concepts' founder; filed December 21, 2010, granted January 8, 2013; Google Patents lists it as active but labels legal status an assumption, not a legal conclusion `[manual, relayed]`) states the fix in the inventor's own words: a "C-shape," unbent, truss-cut aluminum frame "distributes an external force that is focused on one portion of the saw frame across other portions" — addressing a comparable frame-compression and rigidity problem to the one Tenney's 1888 patent describes, in a different frame context. The two patents are comparable precedents, not a proven direct line of development. **Correction to a prior assumption:** the working brief for this run assumed a "split frame" design; no source uses that term. Knew Concepts' own vocabulary is a rigid truss-cutout C-frame, cam-lever or screw tensioning, and — on premium models — swivel blade clamps ("ASD," Adjustable Sawblade Direction) that lock at 0° and 45° to either side. They do not rotate through 360°. "Split frame" should not appear in this entry or be repeated elsewhere in the corpus.

## Human Side
**A cross-trade teaching story, directly sourced and genuinely moving.** Dave Cushman, a craft-technique writer (dave-cushman.net, fetched full text — the same page Wikipedia itself cites for this tool), opens his piercing-saw page with a first-person memory: *"I was lucky in having a very skilled tutor who taught me to use the piercing saw and many other delicate tools when I was a child of six or seven years... his name was Hugh Burn (Huie) and he was a dental mechanic (orthodontist) of considerable ability."* A dental mechanic teaching a young child the piercing saw is a real, named, cross-trade transmission of the exact kind this corpus exists to capture — the tool moving between trades through a person, not a catalog.

**A 25-year professional's own account, which also produced a real design change — a rare and valuable find.** Mark Maxwell, a working goldsmith (mmgoldsmith.com), reviewed the Knew Concepts saw lineup for Ganoksin/MJSA Journal (fetched full text) and wrote candidly about his own long-owned saw: *"My traditional saw frame is one of those longstanding tools. I bought it with my own money when I was 15, and it has all the war wounds you would expect after 25 years of steadfast service."* Switching to the newer design, he broke blades at the clamp's friction points from over-tightening — and Knew Concepts' own representative, replying in the same published piece, stated the company was changing its machining process (adding a tapered entrance to the blade hole) *because of* this feedback. A documented case of a craftsperson's misuse directly reshaping a manufacturer's tooling — the Petroski loop caught in the act, not inferred after the fact.

**The Ganoksin thread's own texture.** Beyond Zaruba's dating claim (see History), **Ron Charlotte** opened the 2003 thread simply asking how old the tool really is; **Peter W. Rowe** relayed a secondhand account of a Philippine jeweler hand-cutting his own blades from plain steel wire with a chisel, "less prone to break" than commercial blades but slower and coarser — a real glimpse of the tool surviving on improvised, homemade blade stock where commercial supply wasn't available. **Niels Løvschal**, from Denmark, closes the thread's substantive exchange with the drawplate correction (see History) and open envy of Zaruba's Morris saw — two collectors, continents apart, trading real technical knowledge in public, twenty-one years before a third poster (Gerald Livings1, 2024) revived the thread asking for a photo that was never posted.

**Trade-crossing technique, documented from a single working craftsperson.** Cushman notes he personally substitutes fret-saw blades for piercing-saw blades in his own (non-jewelry) work because "their tooth form and number of teeth per inch are more appropriate to the wood and plywood components" he's cutting — a first-person, sourced instance of a craftsperson deliberately choosing across this branch's sibling blade types by material, exactly the kind of matching judgment this schema's Matching block exists to encode. Interweave's "Master the Jeweler's Saw: 14 Tips" (fetched, by Tammy Jones, with technique contributions credited to named jewelers **Michael David Sturlin** and **Diane Brooks**) supplies several of the technique points folded into Correct Use and the misuse layer below.

**Not found, honestly.** No injury narrative was located by either research leg. That is a research result, not a risk assessment: the manufacturer-linked and trade safety guidance does document hazards (see Dangerous, below), and this entry does not read the missing narrative as evidence that the tool is harmless. A claimed "500 years of connection between jewelers and watchmakers" (Zaruba, Ganoksin thread) is real texture but unsourced beyond his own framing, and is not treated as documented history in this entry.

## Proof of existence
- **Dated evidence ladder, with the grade of each rung.** No "earliest" claim is made, and no direct descent is inferred between rungs.
  1. 11th century: a metal-framed saw in the Mästermyr chest, a framed-saw analogue without a tensioning mechanism. Reported in a comment on the Lost Art Press page (secondhand report).
  2. 1568: a Jost Amman woodcut of a comb-maker using a frame saw, as reported in the same comment thread (secondhand report; the image itself was not read).
  3. 1676: André Félibien's published drawing of a "petite scie de marqueterie" (cited via Lost Art Press, fetched; a direct document as cited by a secondary source, and a marquetry saw, not this tool by name).
  4. Private testimony: Doug Zaruba's "Morris" frame, self-dated "around the early 1600s" (Ganoksin Orchid, fetched). The owner's own assessment of a private, undepicted object, not an institutional attribution.
  5. Patent records: an 1872 bow/fret-work saw-frame patent US132140A (the reviewer's relay, not read in this pass `[manual, relayed]`), US390996A (1888) and US8,347,513 B2 (2010 filing, 2013 grant), the latter two read in the original run.
- **Patents — a modern mechanism confirmed directly; deep-history patents unconfirmed.** US8,347,513 B2 (Marshall, 2013; Google Patents lists it as active with a legal-status disclaimer) is directly verified for its disclosed mechanism and covers the current rigid-frame mechanism. US390996A (Tenney, 1888) is directly verified and covers general saw-frame tensioning, not this tool by name. A claimed 1883 William Jones patent "for a jeweler's saw" is cited only secondhand (Progress Is Fine blog) and could not be independently retrieved by either research leg — **not treated as confirmed** in this entry.
- **Museum/collection record — not found.** Neither research leg located a specific piercing-saw or jeweller's-saw object at the Smithsonian, the V&A, or the Science Museum Group. Reported as a genuine, checked absence rather than an unchecked gap — this is a real hole in the corpus's proof-of-existence chain for this tool, distinct from a merely unresearched one.
- **Current commercial existence — solid.** Knew Concepts, Grobet, and Pepe Tools all maintain active, currently-sold product lines, directly confirmed via manufacturer and retailer pages (Contenti's Grobet listing fetched with exact price/spec). This anchors the tool's present-day existence firmly even where its deep history remains genuinely uncertain.

## References
| Title/Source | Author/Org | URL or Number | Kind | Verification |
|---|---|---|---|---|
| Knew Concepts — "The Way of the Saw" (technical PDF, blade-gauge table, physics, technique) | Knew Concepts | knewconcepts.com/downloads/The-Way-of-the-Saw-web.pdf | manufacturer, technical | directly verified, fetched in full |
| Google Patents — US8,347,513 B2, "Hand-held saw with rigid frame" (Buster Lee Marshall, 2013) | USPTO / Google Patents | patents.google.com/patent/US8347513B2/en | patent | directly verified, fetched in full |
| Google Patents — US390996A, "Saw-Frame" (Cornelius Tenney, 1888) | USPTO / Google Patents | patents.google.com/patent/US390996A/en | patent | directly verified, fetched in full |
| Ganoksin Orchid — "Jeweler's Saw History" forum thread (2003–2024), named posters Ron Charlotte, Doug Zaruba, Niels Løvschal, Peter W. Rowe, Gerald Livings1 | Ganoksin | orchid.ganoksin.com/t/jewelers-saw-history/18151 | forum, named posters | directly verified, fetched in full |
| Ganoksin/MJSA Journal — "Jewelers Saws Tested: A Hands-On Review" | Mark Maxwell | ganoksin.com/article/jewelers-precision-hand-saw-test/ | trade publication, named professional | directly verified, fetched in full |
| Dave Cushman — "Jeweler's 'Piercing Saw'" | Dave Cushman, ed. Roger Patterson | dave-cushman.net/bee/piercingsaw.html | craft-technique reference, named author | directly verified, fetched in full |
| Cooksongold — "How To Use A Jeweller's Saw" | Cooksongold | cooksongold.com/blog/learn/how-to-use-a-jewellers-saw/ | manufacturer/retailer, technique guide | directly verified, fetched in full |
| Interweave — "Master the Jeweler's Saw: 14 Tips" | Tammy Jones, w/ Michael David Sturlin, Diane Brooks | interweave.com | trade publication, named contributors | directly verified, fetched in full |
| Christopher Schwarz — "A History of Coping Saws in Five Paragraphs" + comments | Lost Art Press | blog.lostartpress.com/2014/02/05 | craft-history blog, named author + commenters | directly verified, fetched in full |
| Wikipedia — Piercing saw | — (citing Lye, Cushman) | en.wikipedia.org/wiki/Piercing_saw | encyclopedia | directly verified, fetched in full |
| Ganoksin — "Basic Sawing Techniques" | Bradney W. Simon | ganoksin.com | trade publication | directly verified, fetched in full |
| Contenti — Grobet Swiss-Style Saw Frame, item #400-393 | Contenti | contenti.com | retailer, exact price/spec | directly verified |
| Progress Is Fine — "Jeweller's saws" (secondhand 1883 William Jones patent claim) | Progress Is Fine blog | progress-is-fine.blogspot.com/2017/06/jewellers-saws.html | blog, secondary citation | fetched, but underlying patent NOT independently confirmed — flagged, not used as fact |
| [[Razor Saw]] (this corpus, Run 287) — cross-cited for the TheRhino/DakkaDakka lineage-misuse account and the mechanical push/pull comparison | Haft corpus | internal | cross-reference | source material independently verified in that entry's own research |
| Knew Concepts / Grobet / Pepe Tools current pricing, exact tension-PSI figures | various retailers | (aggregate) | retailer/snippet | search-snippet level only — held at lower confidence than manufacturer-direct specs |
| Knew Concepts — New Concept Saw instructions | Knew Concepts | knewconcepts.com/downloads/ncsinstructions.pdf | manufacturer manual | read in fix pass 2026-10-16 (fetch-tool summary): 120 spm maximum, lighter tension, cable loop |
| Rio Grande / Knew Concepts — swivelling-clamp instructions (Mk.III) | Rio Grande | products.riogrande.com/content/Instruction-Sheets/KC_Saw_instructions-Mk3-swivel-open.pdf | manufacturer instructions | read in fix pass 2026-10-16: clamps cannot rotate 360°, lock at 0° and ±45° |
| Rio Grande / Knew Concepts — Precision Saw Guide | Rio Grande | riogrande.com/globalassets/knowledge-hub/instruction-sheets/knew-concepts-precision-saw-guide-is.pdf | manufacturer-linked guide | read in fix pass 2026-10-16: eye hazard, corner holes, tension "sings" |
| Ganoksin — "Rules for Tools" | Ganoksin | ganoksin.com/article/rules-for-tools/ | trade publication | read in fix pass 2026-10-16: eye protection, finger in blade path, cut away from yourself |
| Knew Concepts FAQ; Mk.III screw-frame instructions; Cooksongold; Otto Frei listing; US132140A | various | see the reviewer's 2026-07-29 review | manufacturer / retailer / patent | relayed from the review, not re-read in this pass (`[manual, relayed]`) |

## Honest gaps (named rather than papered over)
- No museum or institutional collection record found for this tool at the Smithsonian, V&A, or Science Museum Group — checked directly, not merely unresearched.
- The oldest claimed physical example (Zaruba's "Morris" saw, ~1600s) rests on a private collector's own dating, not an institutional attribution.
- The 1883 William Jones patent claim could not be independently verified — cited only secondhand by one blog, and not treated as fact in this entry.
- No injury narrative found. That is a research result, not a risk assessment; the hazards are documented in Dangerous above.
- Current manufacturer availability of the Knew Concepts powered saw was not established; one retailer listing was sold out.
- No first-person account was found of someone specifically confusing this tool's capabilities with the razor saw's in the *jewelry-trade* forums searched (Ganoksin/Orchid) — the TheRhino account cited above comes from a wargaming-modeling forum via the Razor Saw entry's own research, not from this tool's home trade.
- Exact current pricing and premium cam-lever tension PSI figures are held at retailer-snippet confidence, not independently fetched from the manufacturer directly.
- Reddit (r/jewelrymaking, r/metalworking) and several woodworking-forum leads (LumberJocks, NAWCC) returned no readable content on fetch attempts — could not confirm or deny content there.

## The reviewer's corrections (14)

- `BLOCKER` — 1. Replace the no-danger finding with the documented hazards — Exact claim: “No injury account was located … consistent with a low-energy hand tool”; “Dangerous: genuinely thin”; “no stored mechanical energy beyond blade tension itself”; “a genuine, well-supported absence.”
- `BLOCKER` — 2. Add the starter-hole drilling and material-exposure safety seam — Exact claim: The tool “pairs with … a drill for starter piercing holes,” while the safety section gives no controls for that powered operation or for the materials named.
- `BLOCKER` — 3. Correct the blade-clamp swivel specification — Exact claim: “on premium frames, 360° swivel clamps (‘ASD’) … rotate 45° either direction.”
- `BLOCKER` — 4. Correct the powered-saw specification and status — Exact claim: The Knew Concepts Precision Power Scroll Saw is a “genuine, distinct powered descendant” operating at “0–160 strokes/minute,” with current existence “confirmed across three independent current retailer listings.”
- `SHOULD-FIX` — 5. Correct the Rule of Three and thick-stock exclusion — Exact claim: “Thick stock of any kind” breaks the Rule of Three; material thicker than “roughly ⅛–3/16 inch” is a “structural incompatibility” the blade “can't survive.”
- `SHOULD-FIX` — 6. Separate frame identity, blade identity, and trade name — Exact claim: The jeweller's saw is the frame branch's “third sibling,” distinguished from fret/coping saws by “blade proportion and trade.”
- `SHOULD-FIX` — 7. Remove the unique interior-piercing claim — Exact claim: “no other saw in this corpus can start a cut from the middle of a sheet this cleanly.”
- `SHOULD-FIX` — 8. Correct the fret / marquetry blade conflation — Exact claim: “Fret/marquetry blade — deeper spine, ~1:3 ratio, coarser teeth.”
- `SHOULD-FIX` — 9. Bound blade-reuse advice by the exact frame and blade condition — Exact claim: An adjustable frame “lets a broken blade's shorter remaining stub be re-tensioned and used out rather than discarded.”
- `SHOULD-FIX` — 10. Make blade tension model-specific — Exact claim: “too loose and it snaps under load, too tight and it snaps under its own tension”; the ping test is presented as a universal safe setting.
- `MINOR` — 11. Correct the “order of magnitude” comparison — Exact claim: A coping-saw blade at roughly 18 TPI is “an order of magnitude coarser.”
- `SHOULD-FIX` — 12. Bound “most breakage-prone” and beginner-breakage normalization — Exact claim: It is “the most breakage-prone” saw/blade in the corpus; beginner breakage is “normal, expected … not a sign of user error or a defective tool.”
- `SHOULD-FIX` — 13. Repair the history chronology and evidence labels — Exact claim: Félibien's 1676 drawing is the “earliest documented illustration,” while the same paragraph acknowledges a 1568 Jost Amman woodcut and an 11th-century metal-framed saw; a privately owned “Morris” frame is called an “earliest claimed physical example.”
- `MINOR` — 14. Use patent status and scope carefully — Exact claim: US8,347,513 B2 is “Active” and solves “the same 1888 bulge problem again”; US390996A is the clearest historic statement for the whole branch.