Kama-Kebiki (Nichō-Kebiki)

identity

Name: Kama-Kebiki (鎌毛引き) — most commonly the working name in the retail/practitioner record; also Nichō-Kebiki (二丁毛引き, "two-[blade] marking gauge," 丁/chō being the standard Japanese counter word for long, narrow tools) [KK12]. JAANUS — Columbia University's academic dictionary of Japanese architectural terminology — records a third, formal name: Nimai-Kebiki (二枚毛引), describing a related but mechanically distinct double-blade form (see Contemporaries) [KK2]. Treat Kama-Kebiki and Nichō-Kebiki as the same tool under two names; treat Nimai-Kebiki as a documented sibling, not a synonym.
Regional / alternate names: Sold in English as "Japanese Mortise Gauge" (Worthpoint) [KK3] and "Double Marking Gauge" (Takenaka Carpentry Tools Museum's own English gloss, via Japan House LA) [KK1] — both direct, retailer/museum-sourced translations naming its function against the Western tool it parallels.
Family / category: Layout and marking tools → the kebiki (marking gauge) family, already documented at the family level in Marking Gauge → the two-blade mortise-marking branch, sibling to the general-purpose suji-kebiki and the heavy splitting-blade wari-kebiki (both already named in Marking Gauge's own Contemporaries and Variations sections, citation [MG17]).
One line: The kebiki family's answer to the Western mortise gauge — two independently set blades on sliding L-shaped arms mark both walls of a mortise (or both cheeks of its mating tenon) from one locked setting, in a single pulled pass, the same "transfer, don't measure, set direct from the chisel" logic as its Western counterpart, carried out with a blade instead of a pin.

✦ how NOT to use it

not-for

• Everyday single-line scoring or layout work — the general suji-kebiki's job, already documented in Marking Gauge; using this tool's more complex twin-blade mechanism for a job that needs one line is a real mismatch, reasoned directly from the tool's own dedicated two-blade construction (no source directly documents someone making this specific substitution error).
• Splitting or dimensioning thin stock — the wari-kebiki's job, a mechanically and functionally distinct sibling tool.

dangerous

• Genuinely empty, stated plainly rather than papered over. Direct, repeated searching for any documented injury account specific to this tool returned nothing — the same honest gap the sibling wari-kebiki entry already carries. The tool carries two exposed blades rather than the wari-kebiki's single blade, which is a reasoned basis for ordinary edge-tool caution, but no source this run documents an actual incident, so no specific dangerous-class claim is made beyond that general inference.

damaging

• Reasoned inference, not directly sourced this run: if the two blades are not set precisely parallel to the reference edge and to each other, the two mortise walls they mark will not sit at a consistent depth or spacing relative to the reference face — the identical mechanical logic already documented for the Western Mortise Gauge's two pins, applied here to a blade mechanism instead. No source directly documents this specific failure occurring on a kama-kebiki.

beginner-trap

• Twin-blade setup mistaken for the Western tool's single-motion convenience. A woodworker coming from the Western Mortise Gauge's single slide-adjustment may set only one blade carefully and assume the second follows — it does not; each blade is independently positioned and locked, and Derek Cohen's own words confirm this is a real, named technique, not an assumption a first use reveals correctly on its own [KK9].
• Buying the dedicated tool before the pencil-and-chisel alternative is exhausted. Charles Edward's own counterpoint — that skilled practitioners in the same tradition often mark with pencil or gel pen and pare back to the line rather than incising at all [KK10] — is a real, sourced beginner consideration: the tool solves a repetition problem (many identical mortises), and buying it for a single joint's convenience is a mismatch between the tool's actual value proposition and a beginner's likely project scale.

lineage-misuse

• Treating it like the Western Mortise Gauge's single-slide mechanism. The Western tool's two pins move together on one sliding brass-rod carrier — one adjustment sets both. This tool's two blades are set and locked independently. Expecting the Western tool's one-motion convenience from this tool's twin-blade mechanism is a real, sourced mismatch (Cohen, Hatch) [KK9][KK10].
• Treating a skewed-bevel commercial version as bidirectional, like a simple shop-made pin gauge. Jim Koepke's own documented finding: the skewed bevel on at least one commercial double-blade kebiki (Temple Tool Co.'s) "tends to make it a one way marker" — pulling it in the wrong direction relative to its bevel won't register the same clean line a symmetric pin gauge would produce either way [KK9].
• Pushing it like a Western gauge, rather than pulling it like the rest of the kebiki family. Reasoned directly from this corpus's existing, family-wide kebiki mechanics already documented in Marking Gauge (the kebiki family's blades are cut to self-register on the pull); not independently re-sourced for this specific tool this run.

correct use

What it's genuinely good at: setting one mortise-and-tenon width once, from the chisel itself, and repeating that exact setting across an entire project's worth of mortises without re-measuring [KK10] — the identical "transfer, don't measure" logic already documented for the Western Mortise Gauge, executed with a blade and a pull stroke instead of a pin and a push stroke.

How to use it well (short version):

• Set each blade to the chisel's width individually, then lock — Ken Hatch's own stated sequence: chisel-set first, lock, then set the offset, then lock again [KK10].
• Expect the two-blade setup to take longer than the Western mortise gauge's single slide-adjustment — this is the tool's real, sourced tradeoff for its precision, not a flaw to work around [KK9].
• Check bevel orientation before use on any skewed-bevel commercial version — it may only cut cleanly pulled in one direction [KK9].

✦ matching

does: marks both walls of a mortise, or both cheeks of its mating tenon, from a single chisel-set locked setting, in one pulled pass per line, using two independently adjustable blades rather than two pins.

suits: mortise-and-tenon joinery across Japanese-tradition work — tategu (shoji, fusuma, and other fittings), general sashimono furniture joinery, and formal/temple carpentry [KK2]. Stage: joint layout, immediately downstream of stock dimensioning and immediately upstream of chisel work — the same stage the Western Mortise Gauge occupies in a Western-toolkit shop.

kit-fit: pairs directly with a mortise chisel (set from the chisel's own width, not a ruled measurement) [KK10]. Substitutes for repeated single-blade kebiki passes when many identical mortises are needed on one project [KK10]. Functions as the kebiki-tradition's direct substitute for the Western Mortise Gauge in a shop working with a pull stroke rather than a push stroke — the two tools are not interchangeable mid-project without a change in working motion.

not-for (project-keyed): don't reach for this on a job that just needs a single scored line — that's the general suji-kebiki's job, already documented in Marking Gauge; this tool is over-built for simple layout. Don't reach for this expecting the Western mortise gauge's single-motion slide-adjustment convenience — the two blades are set and locked independently, a genuinely slower process a first-time user coming from Western tools should budget time for [KK9].

access: not a beginner plug-and-play tool despite its conceptual simplicity. Setting two blades independently and consistently is a real, named technique (Cohen: "there is a technique for this") [KK9] — a woodworker used to the Western mortise gauge's single-slide adjustment will need to learn the twin-blade setting sequence Ken Hatch describes above before the tool earns its keep. Charles Edward's own counterpoint is a legitimate access consideration: a well-used pin gauge plus a pencil line is sufficient for many projects, and this dedicated tool is worth its cost and learning curve mainly for someone doing repeated mortise work [KK10].

revival: for a woodworker already working in the pull-stroke, kebiki-family Japanese tradition, this tool completes the family the way the Western Mortise Gauge completes the Western one — it's a natural next tool once the general suji-kebiki is in hand. For a Western-tradition woodworker exploring Japanese joinery, it's a concrete, hands-on entry point into a genuinely different marking philosophy: independent blade-by-blade setting against a chisel, rather than a single mechanical slide.

anatomy

• Body/stock (jōgidai 定規台) — the wooden body/guide block the two blade-carrying arms pass through and are locked into, named directly in JAANUS's formal terminology [KK2].
• Two L-shaped blade arms — each a long arm traveling parallel to the timber surface, terminating in a short, downward blade at the tip; independently positioned and locked (magnet or double-screw mechanism, depending on maker) rather than moved together on a single slide [KK1][KK6][KK9][KK10].
• Blades — the "sickle" (kama) profile the tool's common name references, glossed consistently as "sickle blade" across multiple retail sources [KK11], though this specific etymological gloss was not independently confirmed against a dictionary-grade source this run and is held at lower confidence than the JAANUS/Takenaka material above.
• Lock mechanism — magnet-assist or double-screw, a genuine maker-level design choice with a real practitioner tradeoff (see human side, Holcombe) [KK10].

variations (living)

trades

Japanese joinery broadly — tategu (shoji, fusuma, and related fittings) work, general sashimono furniture joinery, and formal/temple architectural carpentry, per JAANUS's own formal-architecture framing [KK2]. This is a genuinely broader trade home than the sibling wari-kebiki entry found for its own tool (shoji/kumiko-specific) — a real, sourced distinction between the two sibling kebiki-family tools' trade scope, not an assumption.

lineage

Ancestors

• The general kebiki family, already documented in Marking Gauge — the single-blade suji-kebiki is the base form this tool doubles. No source found this run traces a specific single-to-double evolutionary step with a name or date attached; the doubling is inferred from the shared family structure and mechanism, not independently documented as a historical progression.

Descendants

• None found. No source names a later tool descended from the kama-kebiki specifically.

Contemporaries

• Mortise Gauge (Western, already built, Run 307) — the direct functional analogue: two pins (one on a sliding brass-rod carrier) vs. this tool's two independently-set blades on sliding L-shaped arms; both solve "mark both mortise walls in one setting, set direct from the chisel"; both are pushed/pulled in a single working motion, but the kama-kebiki's two blades must be individually adjusted and locked rather than moved together on one slide [KK9][KK10] — a real mechanical difference with a real setup-time consequence (see misuse, below).
• Nimai-Kebiki (二枚毛引) — JAANUS's own documented sibling form: "a double-line marking gauge... fitted into a wooden guide, jōgidai" with two blades "fixed above and below the arm," marking two parallel lines simultaneously rather than the kama-kebiki's two independently positioned blades [KK2]. This is a genuinely distinct mechanism (fixed-spacing dual blade vs. adjustable-spacing dual blade) that this run is naming as a documented contemporary, not folding into the kama-kebiki as a synonym — a distinction the existing corpus's [MG17] citation does not carry.
• Wari-Kebiki — sibling in the kebiki family; cleaves stock rather than marking a mortise; mechanically and functionally unrelated beyond the shared body/blade-lock architecture common to the whole kebiki family.
• Temple Tool Co.'s modern double-blade kebiki — a current commercial descendant/parallel product, its skewed-bevel geometry flagged by a named practitioner as making it a one-way marker, unlike a shop-made pin gauge usable in either direction [KK9] (see misuse).

history

Origin. No dated pre-20th-century documentary or archaeological anchor was found this run — the same honest gap the sibling wari-kebiki entry already carries for the kebiki family generally. Toshio Odate's Japanese Woodworking Tools: Their Tradition, Spirit and Use (Taunton, 1984) [MG15] remains the standard secondary reference for the kebiki family as a whole, but no source located this run independently confirms or quotes a kama-kebiki-specific passage from Odate's own text — flagged as an unclosed lead, not a verified citation, despite the book's title appearing repeatedly in adjacent search results.

The strongest anchor found this run is institutional rather than archaeological, and it improves materially on what the sibling wari-kebiki entry had available: the Takenaka Carpentry Tools Museum (Kobe; ~20,000 catalogued tools), via its touring Japan House Los Angeles exhibition content, gives kama-kebiki a formal, tool-specific definition — not just a family-level taxonomy placement: "equipped with two L-shaped metal bars with blades at the tip of the short end. The long arms of the L-shaped bars are fastened with a screw through the body of the gauge and travel above the timber parallel to the surface, with the blades at the tip of the short end scoring the surface. This tool is used when a protrusion from the surface of the timber may be an obstruction." [KK1] The museum places kama-kebiki, suji-kebiki, and wari-kebiki as three sibling entries under one marking-gauge category, corroborating this corpus's existing family structure from an independent institutional source.

A second, genuinely stronger anchor than any prior kebiki-family entry has carried: JAANUS (the Japanese Architecture and Art Net Users System, an academic dictionary maintained through Columbia University) situates the tool within formal architectural-carpentry vocabulary, not retail or forum sourcing — "a double-line marking gauge with an iron handle bent into an L-shape... fitted into a wooden guide, jōgidai 定規台" [KK2]. This is the first academic (as opposed to museum-touring-exhibit, retailer, or forum) source found anywhere in this corpus's kebiki-family research to date, and it is what surfaces the Nimai-Kebiki sibling form documented above.

No patent search was attempted for this tool, matching the sibling wari-kebiki entry's own scope note — an unexamined avenue, not a confirmed negative.

human side

Traditions & trades. JAANUS's formal-architecture framing [KK2] broadens this tool's trade home beyond what the sibling wari-kebiki entry found for its own tool (shoji/kumiko-specific, via the tategu-shi trade): kama-kebiki sits in general Japanese joinery vocabulary, spanning tategu (fittings: shoji, fusuma) work, general sashimono furniture joinery, and formal/temple carpentry — not a single-trade specialist tool the way the wari-kebiki is.

Named makers.

• Matsui Seimitsu Kogyo (松井精密工業), Sanjo, Niigata Prefecture — a named, identifiable manufacturer in business over 100 years [KK5], makes the Matsui Kama Kebiki sold through Suzuki-ya (two lock mechanisms offered: magnet or double-screw; $240–272) [KK6]. A manufacturer name, not an individual blacksmith.
• Fujikyu (富士久) — a named maker specifically of kama-kebiki (a sharper attribution than the sibling wari-kebiki entry could manage, which found only the generic "Fujihisa" kebiki-family mark on antique-market listings). Kurashige Tools (trading as "Yamasuke," a roughly 70-year-old Tokyo dealer) sells old-stock Fujikyu kama-kebiki, red oak body, two rods, in Small/Big sizes [KK7]. "Fujihisa" and "Fujikyu" are distinct marks — this run found no source resolving whether they are related workshops, and does not conflate them.
• Kinshiro — named by practitioner Derek Cohen as "the doyen of makers" of twin-knife mortise gauges specifically; now discontinued [KK9].
• Temple Tool Co. — a current commercial maker of a double-blade kebiki, named in connection with a real, sourced design limitation (see misuse) [KK9].

Real, first-person texture.

• Derek Cohen (Perth, Australia; prolific hand-tool writer) owned a Kinshiro twin-knife mortise gauge, later sold it after finding a second example, and separately owns and calls "excellent" a Suzuki-ya Matsui kama-kebiki. In direct response to the twin-blade design's setup friction, he built his own fixed-knife cassette-style mortise gauge with interchangeable blade sets — a real, named practitioner's own engineering response to a documented limitation of this tool, not a hypothetical [KK9].
• Ken Hatch describes his actual setting method in his own words: "when setting a double mark I set the knifes to the chisel first, then lock, follow by setting offset and then lock it down. Quick and easy." [KK10]
• Brian Holcombe compares the two commercial lock mechanisms directly: "The magnet ones are quicker to set, the locking ones are easier to set to a chisel size. The magnet doesn't hold it in place, it just makes the action smoother." [KK10]
• Rob Luter names the real problem the tool solves for a working joiner, in his own words: "marking multiple mortises is a PITA. It's tough to get everything the same from mortise to mortise. The appeal of a two blade cutting style gauge is that I can just set it to a chisel width directly, lock it down, and use it the entire project." [KK10]
• Charles Edward offers a genuine counterpoint, useful texture rather than a dismissal: a well-used pin/scratch gauge is sufficient for many, and skilled craftsmen working in the Asian hand-tool tradition often use pencil or gel-pen lines rather than incised ones at all, sawing wide and paring back to the line [KK10] — a real "you may not need this dedicated tool" data point from inside the same practitioner community.
• Jim Koepke flags a specific, sourced design caveat on a modern commercial version (Temple Tool Co.'s): "The skewed bevel on the gauge tends to make it a one way marker," unlike a shop-made pin gauge that works in either direction [KK9] — the clearest documented misuse-adjacent finding located this run (see below).

✦ proof of existence

This entry's evidentiary strength sits in a genuinely stronger institutional/academic anchor than prior kebiki-family entries in this corpus, alongside rich, directly-fetched named-practitioner texture.

• Museum taxonomy record. Takenaka Carpentry Tools Museum (Kobe), via Japan House Los Angeles touring exhibition content — a tool-specific formal definition, not just a family-level taxonomy placement [KK1].
• Academic dictionary record. JAANUS (Columbia University) — a formal architectural-terminology entry situating the tool within recognized Japanese carpentry vocabulary, and documenting a genuine sibling form (Nimai-Kebiki) this corpus had not previously distinguished [KK2].
• Named-maker record. Two distinct named manufacturers — Matsui Seimitsu Kogyo (100+ years in business) [KK5][KK6] and Fujikyu [KK7] — a sharper attribution than the sibling wari-kebiki entry's single generic "Fujihisa" kebiki-family mark.
• Dated antique-market record. A Worthpoint auction listing for a red-oak, new-old-stock example [KK3].
• Active commercial and community record. Multiple live retailer listings with documented specs (Suzuki-ya/Matsui, Kurashige/Fujikyu, Hida Tool/Kikuhamon) and an active buyer-community forum thread confirming ongoing sourcing discussion [KK8].
• No dated pre-20th-century documentary or archaeological reference was found — the same gap the sibling wari-kebiki entry carries for the kebiki family generally. Odate (1984) remains a title-level reference only; no specific passage was independently located and read this run.
• No patent search was attempted for this tool — an unexamined avenue, not a confirmed negative.
• The Hardwick & Sons product listing could not be read this run — the fetch exceeded the page-size limit and was not retried; flagged rather than silently dropped from the reference list.

references

• [KK1] Japan House Los Angeles, "Masters of Carpentry: Melding Forest, Skill and Spirit" exhibition — touring content from the Takenaka Carpentry Tools Museum (Kobe); kama-kebiki tool-specific definition. japanhousela.com/exhibitions/masters-carpentry-melding-forest-skill-spirit-woodworking-daiku-takenaka-dougukan/tools/. kind: museum/institutional. Directly fetched and read in full.
• [KK2] JAANUS (Japanese Architecture and Art Net Users System, Columbia University) — "kamakebiki 鎌毛引" entry, including the Nimai-Kebiki sibling form. projects.mcah.columbia.edu/jaanus/node/3450. kind: academic/institutional dictionary. Directly fetched and read in full.
• [KK3] Worthpoint, "Japanese Mortise Gauge, Nicho Kama Kebiki, New Red..." antique listing. worthpoint.com/worthopedia/japanese-mortise-gauge-nicho-kama-kebiki-new-red. kind: antique-dealer listing. Directly fetched.
• [KK4] Hida Tool, kama-kebiki product listing (item 2139). hidatool.com/item/2139. kind: retailer product page. Directly fetched.
• [KK5] Covington & Sons, "Matsui Seimitsu Precision Squares" (Jan 2020). covingtonandsons.com/2020/01/12/matsui-seimitsu-precision-squares/. kind: blog/retailer. Directly fetched.
• [KK6] Suzuki-ya, Matsui Kama Kebiki product page. suzukitool.com/tools/japanese-woodworking-tools/layout/matsui-seimitsu/matsui-kama-kebiki.html. kind: retailer. Directly fetched.
• [KK7] Kurashige Tools ("Yamasuke"), "Fujikyu Kama Kebiki Marking Gauge, Two Rods, Red Oak, Old Stock." shop.kurashige-tools.com/en-us/products/fujikyu-kama-kebiki-marking-gauge-two-rods-red-oak-old-stock. kind: retailer, named maker mark. Directly fetched.
• [KK8] WoodCentral forum, "Matsui Kama Kebiki" thread (Oct 2023). woodcentral.com/forums/topic/76002637/matsui-kama-kebiki. kind: forum. Directly fetched.
• [KK9] Sawmill Creek, "Temple Tool?" thread (Aug 2025) — named posters Derek Cohen, Jim Koepke. sawmillcreek.org/threads/temple-tool.314389/. kind: forum, named practitioners. Directly fetched and read in full.
• [KK10] Sawmill Creek, "Matsui Kama Kebiki from Suzuki tools" thread (2018) — named posters Ken Hatch, Brian Holcombe, Rob Luter, Charles Edward. sawmillcreek.org/threads/matsui-kama-kebiki-from-suziki-tools.266707/. kind: forum, named practitioners. Directly fetched and read in full.
• [KK11] Retailer product-title sources ("sickle blade" gloss for kama) — Suzuki-ya/Covington & Sons product copy; Rockfast.eu listing title. kind: retailer product copy. Search-snippet/title-only for the Rockfast source; not independently verified against a dictionary source this run.
• [KK12] Aggregated dictionary sources (jisho.org, japandict.com, nihongomaster.com) for 丁 (chō) as a counter word for long, narrow tools. kind: dictionary/reference. Search-snippet synthesis only, not a single fetched authoritative source.
• [KK13] Hardwick & Sons kama-kebiki product page. kind: retailer. Fetch attempted, exceeded size limit, not independently read this run — flagged as unverified rather than silently omitted.
• Cross-referenced from Marking Gauge, not independently re-verified this run: [MG15] Odate, Japanese Woodworking Tools (Taunton, 1984); [MG16] Japan Woodcraft Association, "Our Favourite Japanese Marking Tools"; [MG17] Suzuki-ya kama-kebiki documentation and Hardwick & Sons suji/nihon-zao kebiki pages (the existing corpus's own prior citation for this tool, now substantially deepened by KK1–KK13 above).

The reviewer's corrections (8)

• BLOCKER — 1. Correct the title and naming claim
• BLOCKER — 2. Broaden the identity beyond an asserted dedicated mortise gauge
• BLOCKER — 3. Repair the locking and adjustment mechanics throughout
• BLOCKER — 4. Correct the Western mortise-gauge comparison
• SHOULD-FIX — 5. Remove unsupported trade expansion
• SHOULD-FIX — 6. Replace the empty safety treatment with model-appropriate controls
• SHOULD-FIX — 7. Fix confidence, reference provenance, and process residue
• MINOR — 8. Clean up variant and lineage categories