Plug Cutter

Identity

• name: plug cutter (also wood plug cutter). In boatbuilding the finished plug is a bung; "bung cutter" occasionally names the tool [PC3].
• family / category: Boring & Fastener-Concealment Tools — sibling to the Counterbore (which prepares the recess the plug fills) and the Countersink; related to the Dowel & Tenon Cutter (Hollow Auger).
• one-line (review fix 7): a cutter defined by what it produces — a short cylindrical, tapered or hybrid wooden plug, usually face-grain, sized to fill a matching counterbore over a fastener. Many are hollow cutters with internal cutting edges, but the position and shape of the cutting edges, the centering feature, relief, maximum plug length and intended machine vary by design and determine use.
• four subtypes (review fix 4):
  • shallow plug cutters, often no-pilot — commonly drill-press-only;
  • tapered or hybrid plug cutters (e.g. Veritas Snug-Plug: constant-diameter lead into a 3° included flare);
  • self-centering, handheld-rated plug cutters (e.g. Montana Brand: retractable guide pin, two blades, 1/4″ hex shank);
  • manufacturer-rated combined dowel/plug/tenon cutters (e.g. Lee Valley's carbide-tipped dowel, plug and tenon cutters). Interchangeability with tenon cutters is model-specific.

✦ How NOT to use it

• not-for: cutting tenons with a cutter not rated or sized for them; expecting a hole saw or Forstner bit to make furniture plugs.
• dangerous (review fix 5 — the holding finding). A cutter that binds can catch the stock and spin it, or wrench the drill.
  • Regulator and manufacturer controls first: clamp the stock or use a hold-down fixture — never the hands (OSHA drill-press eTool; OSHA 3170) [PC-O1][PC-O2]; guards in place; eye protection; hair, clothing and jewelry controlled; no gloves near rotating machinery; chuck key removed; stop before adjusting (CCOHS drill presses) [PC-C1]; for hand drills, clamp small stock, never hold it with one hand, keep balance, and disconnect before freeing a jam (CCOHS powered hand drills) [PC-C2]; follow the cutter's rated power source and speed (Lee Valley) [PC-LV].
  • Injury evidence, second: cliffordpope (YBW Forum, Nov 28, 2008) describes standing on scrap stock and drilling handheld: "The slightest variation from vertical entry causes the cutter to bind in the wood and the next thing I knew the wood had been whisked from under my foot and was spinning and oscilating violently on the end of the drill. The second attempt I stood with both feet on the wood and found myself thrown off my feet with a bruised wrist from the kicking drill" [PC18]. This is first-hand evidence of the catch-and-rotation mechanism OSHA describes.
  • Unsafe improvisation, not a competing practice: a later post on the same thread describes foot-bracing stock against a handheld drill as routine. It is evidence that people improvise, not that the method is acceptable. Do not foot-brace or hand-hold the stock (review fix 5).
  • Bandsaw release: small round pieces on a bandsaw add hand-placement and retrieval hazards; see Correct use [PC3].
• damaging: plug grain at 90° to the surrounding grain (elliptical shrinkage shows) [PC2]; burning from slow feed or a dull cutter [PC22]; the cutter striking the table, fence or clamp; prying a plug with the drill energized or in the wrong pry path (can chip the cutter or the work); aggressive cross-grain trimming tearing a proud plug below the surface (use tape and work down to it) [PC16].
• beginner-trap: assuming any plug cutter works handheld — check the model's rating; not test-fitting a batch (fit varies by brand and runout) [PC16][PC-V]; treating "always glue" or "never glue" as universal — choose by project and vessel specification [PC2][PC3]; assuming a hex shank permits impact use.
• lineage-misuse: confusing a plug cutter with a hole saw or Forstner bit; assuming every plug cutter is a tenon cutter, or that none is — model-specific (review fix 4).

Correct use

The cutter manufacturer's instructions control (review fix 5). Check the model's rated power source, speed, depth and release method before cutting.

• drill-press-only cutters (review fix 5; OSHA, CCOHS, Lee Valley):
  • Clamp the stock to the table or a suitable fixture — never hold it by hand (OSHA: hand-held stock catching and rotating on a drill press is a common accident; use a hold-down fixture) [PC-O1][PC-O2].
  • Use the specified speed and the guards; keep the cutter sharp and securely mounted; remove the chuck key.
  • Wear eye protection; secure hair and loose clothing; remove jewelry; no gloves near rotating machinery (CCOHS) [PC-C1].
  • Feed steadily and clear chips as the maker instructs — not by hand.
  • Stop and disconnect before clearing a jam, changing setup, or extracting a plug.
• handheld-rated models only: clamp the stock; use the specified drill and speed; keep a balanced stance and two-handed control where applicable; follow the model's instructions (CCOHS powered hand drills: clamp small stock, never hold it with one hand; disconnect before freeing a jam) [PC-C2]. A guide pin can help establish the start, but safety still depends on clamped stock, cutter geometry, drill type, speed, torque reaction and posture.
• depth and release (review fix 6): follow the cutter's depth and plug-release instructions — some call for snapping plugs free, some have depth stops or side ejection, some allow bandsaw release from flat stock [PC-VL][PC-A2]. Never let the cutter contact the table, fence or clamp. If sawing plugs free, keep the stock flat and supported, use an appropriate fence or jig and a push device, keep hands clear, and stop the saw before retrieving small pieces; the ACBS article carries a strong bandsaw warning [PC3]. A handsaw is a lower-speed alternative some practitioners prefer [PC15]. Before prying a plug out with a screwdriver, stop and disconnect the drill or press and keep hands out of the release path.
• grain-matching: mark grain reference lines on the stock before cutting [PC15]; align plug grain with the surrounding grain — a plug at 90° shrinks elliptically and shows [PC2]; dry-fit to pick matches.
• installation (review fix 3): align the grain; use the adhesive or bedding system appropriate to the joint, finish, environment and future service; tap until resistance; allow cure before trimming (Veritas care label) [PC-VL]. Straight plugs may benefit from glue's swelling; tapered and hybrid profiles rely more on interference fit [PC16][PC7].
• heat: feed steadily and keep the cutter sharp; burning is a documented failure (UK Workshop thread on a Veritas cutter in oak) [PC22]. Sharpen per the maker — Veritas: hone face and bevel and keep teeth equal in height [PC-VL].
• flush-trimming: painter's tape around the plug, then plane, pare or sand down to the tape [PC16][PC15].

✦ Matching — for the app's read

Match fields (the reviewer schema notes):

• output: short decorative or repair plug; diameter; straight, tapered or hybrid profile; maximum usable length.
• work material: species and grain; dry or green stock only where the maker or practice supports it.
• power source: drill press only · handheld-rated drill · brace · product-specific combination.
• workholding: flat stock clamped to the table, a jig/fence, or the maker's specified setup.
• project fit: furniture fastener concealment; cabinetry; boat bungs; repairs; ornamental contrasting plugs (Maloof) [PC19]; insulation-retrofit sealing (oversized cutters) [PC6]; dowel/tenon work only where the model is rated for it (Lee Valley combined cutters) [PC-LV].
• companion operations: matching counterbore (Counterbore); safe release method; adhesive or bedding choice; cure; flush trimming.
• exclusions: a conventional hole-saw slug as a furniture plug; a deep structural tenon where the cutter lacks capacity or rating; handheld use where the maker prohibits it.
• does: cuts short plugs from stock the maker controls, to conceal or seal over fasteners — matched invisibly or contrasting by design.
• kit-fit: pairs with a counterbore, a drill press (for no-pilot cutters), a clamp or fixture, a model-appropriate release method, tape and a plane/chisel/sanding block for trimming.
• tenon boundary (review fix 4): at the operation level, a shallow cosmetic plug and a structural round tenon are different outputs; at the product level, some cutters are built and rated for both. Capacity and manufacturer-rated use settle the match.
• access: approachable with a drill press, a clamp and the steps above (Rockler's how-to) [PC-A2]. Handheld use depends on a model rated for it.
• revival: Maloof's shift from matched to contrasting ebony plugs — hide the fastener, or make the plug part of the design [PC19].

Anatomy

• output-defined (review fix 7): the plug's diameter, profile (straight, tapered, hybrid) and maximum length are the key specifications.
• cutting edges: many are hollow with internal lips/teeth and a clearing lip (Resche 1892) [PC4]; edge position and shape vary by design.
• profile: straight; fixed taper; hybrid constant-diameter-plus-flare (Lee; Veritas Snug-Plug, 3° included flare after a constant-diameter lead) [PC7][PC-V]; increasing taper (Sevack) [PC8]; radial relief (Wirth et al.) [PC9]. Veritas notes the effect of drill-press runout on fit [PC-V].
• centering: none (drill press supplies it); spring or retractable guide pin (Smith 1871 already had spring centering [PC-S]; Montana Brand today [PC21]); other geometry (US 4,595,321) [PC-R].
• shank and drive: round shank for brace or chuck; 1/4″ hex on some current handheld products. Montana Brand states its self-centering cutter is impact-driver compatible — that claim is for that product only, and a compatible shank is not permission to use impact action unless the maker says so (the reviewer mechanical notes) [PC21].
• depth stops and ejection: some cutters have depth stops or side ejection; others rely on snapping or sawing plugs free (review fix 6).

Variations (living)

• shallow no-pilot cutters — drill-press-only per typical instructions (Rockler demonstrates drill-press use with a clamped fence) [PC-A2].
• tapered/hybrid cutters — some current tapered or hybrid cutters (Veritas Snug-Plug); not claimed as the market default (review fix 7) [PC-V].
• self-centering handheld-rated cutters — Montana Brand [PC21]; Sellers's Hitachi/Kobalt-branded cutter [PC17].
• combined dowel/plug/tenon cutters — Lee Valley carbide-tipped series, drill-press only, with diameter/material-specific speed limits [PC-LV].
• oversized insulation-retrofit cutters — Cunniff 1981; tapered plugs for sheathing holes are sold by insulation suppliers [PC6].
• tenon cutters (e.g. Lumberjack Tools) — made for round tenons on log-furniture stock; overlap with plug cutters is product-specific [PC13].

Trades

• Furniture making and cabinetmaking — counterbore-and-plug concealment; contrasting plugs as ornament [PC19].
• Boatbuilding and restoration — bungs over screws; adhesive or bedding per the vessel's construction and restoration specification [PC2][PC3][PC-WB].
• Carriage-body work (historical) — Smith's 1871 patent application [PC-S].
• Chairmaking — Schwarz's practitioner tenon technique; combined cutters where rated [PC12][PC-LV].
• Insulation retrofit — oversized cutters [PC6].

Lineage

• trunnels are a different object. The treenail/trunnel is a driven structural wooden peg; the plug cutter's output is a cosmetic or sealing plug over a fastener [PC1]. Kept apart.
• a selected patent sequence (review fix 8). US patents document recurring attempts to control centering, taper, ejection, heat, breakage and handheld stability from at least 1871 through the late twentieth century. This is a selected record of design responses, not proof of invention or a complete lineage. Citation by a later patent establishes awareness of prior art, not direct descent; uncited connections below are thematic parallels.
  • US 117,786 — Smith, patented August 8, 1871, "Improvement in plug-cutters for wood-workers": a brace-driven plug cutter for carriage-body work, already with adjustable cutting lips, taper and a spring-loaded centering device [PC-S]. It does not prove Smith invented the plug cutter; it is a substantially earlier documented US example.
  • US 473,231 — Uriah H. Leffel, filed January 19, 1891, patented April 19, 1892, "Plug-cutter": centering, a beveled plug, ejection, and possible gang use [PC-L].
  • US 475,560 — Ernst C. Heydenreich, filed December 28, 1891, granted May 24, 1892: a brace-driven cylindrical cutter with a spring-loaded internal chamfering knife to bevel the plug's leading edge [PC5].
  • US 476,312 — Friedrich Emil Resche, filed December 26, 1891, granted June 7, 1892: hollow stock with cutting teeth, a clearing tooth, and a spring-actuated ejector with a centering point. Resche argued that tapered plugs "only bear at one point on the sides of the hole" [PC4]. Resche and Heydenreich filed two days apart and were granted two weeks apart — near-contemporaneous patent activity, nothing more (review fix 1).
  • US 4,295,763 — Cunniff, 1981: a plug cutter for the insulation trade, resealing holes drilled in exterior sheathing for blown-in cellulose, with two taper angles [PC6].
  • US 4,595,321 — "Rotary plug cutting tool" (1986): a design intended to reduce skipping and gouging during handheld operation and improve heat and ejection behavior [PC-R] — evidence that handheld stability has been addressed by geometry other than a center pin.
  • US 5,213,456 — Leonard G. Lee (Lee Valley Tools), filed 1991, granted 1993 (review fix 2). Lee's background criticizes both cylindrical plugs (they may gap, burn, tear or rotate) and earlier tapered plugs (they may bear only on a narrow ring and rock, or provide insufficient glue area). Lee claims a hybrid profile — a rounded entry, a constant-diameter portion and a flared portion — to preserve initial alignment and glue area while gaining a final interference fit. It is a synthesis of two failure modes, not a reversal of Resche [PC7].
  • US 5,401,125 — Lloyd Sevack, 1995: cites Lee's patent; a continuously increasing taper intended to suit both hardwood and softwood with one cutter, plus a through-shank hole to push out a jammed plug [PC8].
  • US 5,810,524 — Wirth, Sanger and McCool (assignee Woodworker's Supply), 1998: radial relief on part of the blade's inner face, with the stated purposes of reducing burning and premature breakage — read from the primary record [PC9].
  • Removed: the "US 2,748,817 (Walter I. Stearns, 1953/56)" citation. Lee's own cited list shows US 2,748,812A, "Saw-table extension"; no plug-cutter patent by that number and inventor is verified (review fix 2). The "US 2,027,139 (~1936)" date inference is also removed.
• not the same tool:
  • hole saw — a conventional hole saw is normally a poor substitute for furniture plugs: it commonly uses a pilot, cuts a kerf around a larger waste slug, and does not promise the plug diameter or finish a matching counterbore needs. Functional unsuitability, not mechanical impossibility (the reviewer mechanical notes).
  • Forstner bit — removes the material inside its diameter as shavings; it is a counterbore tool, not a plug maker.
  • dowel/tenon cutter — see subtypes; overlap is model-specific.

History

• Early documented cutters were brace-driven (Smith 1871; Leffel, Heydenreich and Resche 1891–92); later examples were designed for drill presses or handheld power drills. No transition dates are claimed (review fix 10).
• Makers. W.L. Fuller, Inc. (Warwick, RI) — per McFeely's spotlight and the company, Warren L. Fuller Sr. began designing tools in the 1930s while building boats; the first catalog appeared in 1945 [PC10]. Big Horn Corporation (Karen Cody), acquired by American General Tool Group in 2015 [PC11]. These are company-history statements, not dated catalog evidence.
• Boatbuilding practice varies (review fix 3). The Antique and Classic Boat Society's bung article describes "a drop of wood glue" in each hole over the recessed screw head [PC3]. Fine Woodworking's boatbuilder-method piece discusses varnish bedding for color and reversibility, and its installation text permits "varnish (or glue)" [PC2]. WoodenBoat School treats adhesive choice as part of a context-specific refastening method [PC-WB]. No universal rule is drawn.

✦ Human side

• Leonard G. Lee, founder of Lee Valley Tools — named inventor on US 5,213,456, ancestor of the Veritas Snug-Plug line [PC7].
• Lloyd Sevack — 1995 patentee citing Lee [PC8].
• Warren L. Fuller Sr. and Jr. — W.L. Fuller, Inc. [PC10].
• Joel Terbrueggen (Antique & Classic Boat Society; Motor Boat Garage, Cincinnati) — the "bung stick" (matched plugs on a strip, snapped free at install), grain alignment so bungs "seem to disappear," a drop of wood glue per hole, and a strong bandsaw warning with an injury image [PC3].
• A boatbuilder correspondent via David Richards, Fine Woodworking (2009): plugs "will shrink a wee bit and become elliptical... very noticeable if the plug's grain is 90° to the surrounding grain" [PC2].
• Sawmill Creek, "Matching grain with wood plugs" (2025) — practitioner evidence: Maurice Mcmurry (grain reference lines); Rob Sack (treats plugs as deliberately visible); Jim Becker (frees plugs with a screwdriver); Jimmy Harris (avoids the bandsaw for small round pieces); Brian Runau (color mismatch after grain-matching) [PC15].
• Sawmill Creek, "Plug cutter - tapered vs standard" (2013) — Lee Schierer (glue swells a straight plug's compressed surface; painter's-tape trimming); Thomas Hotchkin; Tom Ewell (fit varies by brand) [PC16].
• Paul Sellers (2013) — reports a spring-center-pin cutter working in a handheld cordless drill, and that ordinary no-pilot cutters "spin off course straight away" without a drill press [PC17]. Practitioner evidence for one product.
• Christopher Schwarz — Chairmaking on the Cheap(er), Part 1 (Lost Art Press, 2022): uses a plug cutter in a handheld drill or brace on a tapered, vise-held chair-leg blank to cut tenons, noting "Most plug cutters warn you to use the tool only in a drill press" [PC12]. Attributed to Schwarz (the reviewer source notes). A practitioner technique that may be within the purpose of some combination cutters and outside the instructions of others; it does not override a cutter maker's drill-press-only direction.
• Sam Maloof — early rockers used matched plugs; later he used contrasting ebony plugs as a signature, still followed by the workshop [PC19].
• YBW Forum, "Plug cutters" (2008) — cliffordpope's first-hand account of a handheld cut catching and spinning the stock (see How NOT to use it) [PC18].
• Museum record: none for a plug cutter was found in the sources searched; the Smithsonian "pluggers" record is a dental instrument (excluded) [PC20].

✦ Proof of existence

• Primary patent records read: US 117,786 (Smith, 1871); US 473,231 (Leffel, filed 1891, granted Apr. 19, 1892); US 475,560 (Heydenreich, 1892); US 476,312 (Resche, 1892); US 4,295,763 (Cunniff, 1981); US 4,595,321 (1986); US 5,213,456 (Lee, 1993); US 5,401,125 (Sevack, 1995); US 5,810,524 (Wirth/Sanger/McCool, 1998) — a selected sequence, not a complete genealogy.
• Current manufacturer instructions: Veritas Snug-Plug product page and care label; Lee Valley combined-cutter instructions; Montana Brand product page.
• Museum record: none located in the sources searched; the Smithsonian "pluggers" lead excluded as a dental instrument [PC20].
• Open: Montana Brand's claimed patent (US 7,578,324) not read.

References

The reviewer's corrections (10)

• BLOCKER — 1. Repair the origin story and patent chronology — Exact claim: “The earliest patents are US476312 (Resche) and US475560 (Heydenreich),” together with the description of “same-week 1892” rivals “sixteen days apart,” and the open-gap statement that US117786 and US473231 “could not be …
• BLOCKER — 2. Correct the Lee “reversal” and the 1956 citation — Exact claim: “Resche argues against tapered; Lee in 1993 reaches the opposite conclusion,” plus the citation-chain statement identifying “US2748817 (Walter I. Stearns, 1953/56).”
• BLOCKER — 3. Replace the categorical boatbuilding adhesive rule — Exact claim: “Boatbuilders traditionally do not glue” bungs and the matching instruction not to glue a boatbuilding bung when later fastener access matters.
• BLOCKER — 4. Remove the absolute plug-cutter/tenon-cutter boundary — Exact claim: A plug cutter “cannot replace, and cannot be replaced by” a dowel/tenon cutter, despite the later off-label chairmaking example.
• BLOCKER — 5. Replace anecdotal safety equivalence with authoritative controls — Exact claim: The injury account is followed by another poster's foot-bracing method as an unresolved “contradiction,” while a spring center pin is presented as the handheld-safe exception.
• SHOULD-FIX — 6. Make cutting, freeing, and trimming advice model-specific — Exact claim: “Set a fence or stop so the cutter just breaks through the far edge,” free plugs with a screwdriver or bandsaw, and pair the tool generally with a bandsaw/dovetail saw and screwdriver.
• SHOULD-FIX — 7. Reduce unsupported universals and confidence — Exact claim: The plug cutter is universally a “hollow, internally-toothed cylindrical” tool; tapered/self-locking geometry is the modern default; the center-pin design is the singular handheld exception; and the evidence merits “MEDI …
• SHOULD-FIX — 8. Distinguish a selected design sequence from direct lineage — Exact claim: “A genuine, five-patent, self-narrated Petroski chain running 1892–1998,” plus “five inventors across 106 years.”
• SHOULD-FIX — 9. Clean the evidence layer and remove process residue — Exact claim: The reference and proof sections rely in places on root URLs, search summaries, forum recollections, and notes about the research process or model/research passes work.
• MINOR — 10. Remove or prove the power-drilling and commercial-history claims — Exact claim: The tool “predates power drilling by at least four decades,” followed by a mid-1930s-to-1950s shift and brand/manufacturer history.