# Shinto Saw-Rasp Hewn Tool Library · https://hewn.build/tools/shinto-saw-rasp 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: "Shinto Saw-Rasp." Hewn Tool Library, hewn.build/tools/shinto-saw-rasp. Reviewed 2026-07-27. --- ## identity - **Name:** Shinto saw-rasp (also "Shinto rasp," "saw rasp," "saw-blade rasp"). "Shinto" is the **brand/manufacturer name**, not a tool-type term — the tool is a *saw-blade lattice rasp*, of which Shinto is the dominant maker. [Lee Valley; Popular Woodworking (Schwarz, 2006); Charnwood.] - **Regional / trade names:** "saw rasp," "Japanese saw rasp" (retail framing). Sold by some UK retailers under the brand line "**Asahi** Quality Japanese Carpentry Tools." [Charnwood SR10/SR30 product pages.] - **Family / category:** Toothed-steel abrading/shaping **hand** tool — a rasp or file in *job*, but in the corpus its tooth is a **saw tooth** and its working surface is an **assembly of blades**, not a surface formed in a single rasp body. ("Abrading" here is a corpus-family choice, not a claim that it works like grit: it removes chips with saw-like teeth.) - **One line:** A holder carrying ten thin saw-toothed steel strips, toothed on both edges and joined into a cross-hatched lattice, that shapes wood quickly and resists clogging because the open, non-parallel lattice leaves debris somewhere to go. **Use the blade in its manufacturer-approved handle or holder; a bare replacement lattice is a sharp component, not a hand grip.** --- ## ✦ how NOT to use it *The Shinto's misuse layer: the teeth are* saw *teeth on an open, toothed lattice (both faces and the edges are live), the face is mostly flat (poor for hollows), and the tool removes material* faster than a beginner expects *(over-removal is the signature ruin).* **NOT-FOR (jobs it should never do):** - **Use as a handleless tool.** A replacement blade has no safe place to put the hand: both faces and exposed edges are toothed. Do not hold or use a bare replacement lattice. (Fix 1.) - **Finishing / a ready-to-finish surface.** Etto, on pine: "smooth but not as smooth as... a block plane or 240-grit sandpaper. It is not a surface ready to be finished." Sellers and Schwarz say the same. [Etto; Paul Sellers; Popular Woodworking.] - **Tight concave or hollow work.** A flat broad face is poorly suited to tight concavity; Sellers: "its main downfall is there is no round face, making it mostly useable on flat and convex surfaces, with hollowing out of the question." That is a geometry and matching limitation of the common flat-faced models, not a physical impossibility for the family (Fisher's and Bryan's described curved or flexing forms; per the reviewer). The luthier Tom Bills set it aside for this reason. [Paul Sellers; The Art of Lutherie; WoodCentral; Sawmill Creek.] - **Fine detail or precision joinery to a line.** A medium shaping tool, too fast and coarse for working to a fine line. [Popular Woodworking.] - **Any nonwood material without the hazard gate below.** **MATERIAL HAZARD GATES (read before any nonwood work, and before wood that is coated or composite).** The materials in the retailer list do not share one dust or swarf hazard. "The rasp works on it" is not "a safe, manufacturer-approved application." For **every** nonwood match, require all of: (a) **identification** of the substrate, any coating or adhesive, and its SDS; (b) **compatible capture or ventilation, or wet controls,** for the actual contaminant; (c) **eye, skin and respiratory protection selected for that contaminant** (not a one-line "dust extraction/respirator"); (d) **safe waste cleanup.** Substrate by substrate: - **Wood and MDF.** Wood dust: see below. MDF involves wood dust and potentially formaldehyde and resin-related exposure; HSE's MDF guidance supports local exhaust and HEPA-vacuum use, and contradicts treating MDF as merely another shaping material. `[manual, relayed]` (HSE MDF guidance) - **Plasterboard / joint compound, and soft stone.** Joint compound can generate high total and respirable dust and sometimes respirable crystalline silica, and stone may contain silica; NIOSH's hand-sanding drywall page supports effective vacuum-control systems. `[manual, relayed]` (NIOSH drywall hand sanding) - **Cured or partially cured epoxy.** Epoxy dust can cause skin and respiratory exposure and sensitization, especially when not fully cured; WEST SYSTEM's overexposure page supports ventilation and suitable respiratory protection when sanding epoxy. `[manual, relayed]` (WEST SYSTEM) - **Painted or coated surfaces.** Paints and coatings may contain hazardous pigments; identify before working. - **Metals (brass, aluminium, mild steel).** Sharp swarf and material-specific dust; the practitioner report that the tool cuts them is not a maker approval, and cutting metal spends blade life (Small Boats Monthly). Keep as a low-confidence observation, not a primary match. - **Plastics and foams.** Composition varies; identify the material and its SDS first. - **Hoof wall (farriery).** Specialist practice, not a casual material match. **DANGEROUS (misuse that injures the user):** - **The exposed lattice cuts skin fast.** The teeth are sharp saw teeth on an open face. Workshop Heaven's own listing warns: "Mind your fingers when using — it is very sharp." A secondary review puts it more vividly ("eats flesh like it does wood"; SOFT). No first-person injury account with a named source was located; that is a research result, not an assessment that the tool is safe, and the hazard follows from the geometry and the maker-side warning. [Workshop Heaven; WoodworkWizardry — SOFT.] - **No safe back on a bare blade.** Both broad faces and the edges carry teeth, and the saw-type teeth are described as cutting in either direction (Sawmill Creek — Matthews). Any hand steadying a bare blade is on live teeth. **Do not hold, grip or steady a bare replacement lattice; use the approved holder.** Handle and transport with the teeth covered. (Fix 1, per the reviewer.) - **Catch-and-lurch if you force it.** It removes "chainsaw-like" amounts of material; pushed too hard it can grab and jump. [CLC; Amazon review — SOFT.] **Secure the work, use controlled pressure, keep the stroke path clear of both hands.** A one-handed model used with an unsecured workpiece is the setup for this. - **Inspect before and during use:** check the handle and holder for looseness and the lattice for damage or loose blades; stop if either is compromised. - **Eyes.** Chips and swarf, and brushing or cleaning the lattice, can throw debris; wear eye protection appropriate to chips and swarf. - **Wood dust: a serious, long-latency health hazard.** The IARC classified occupational wood dust as carcinogenic to humans (Group 1), linked to sinonasal cancers. [IARC Monograph Vol. 62, 1995 — FIRM.] The IARC page does not supply a complete hazard plan for the nonwood materials above. Use source capture or compatible wet methods, safe housekeeping and contaminant-appropriate protective equipment; do not treat "dust extraction/respirator" as a one-line universal control. **DAMAGING (misuse that ruins the tool or the work):** - **Over-removal — the signature ruin.** It cuts far faster than its mild looks suggest; "takes off a ton of material in a short period of time, even on the fine side." On a workpiece that is irreversible. [CLC; Amazon — SOFT; WoodCentral.] - **Clogging at the blade junctions.** The clog resistance is real but not absolute: Cunningham notes that where blades sit shoulder-to-shoulder at the rivets "little bits of material get stuck," so resinous wood can still pack those points and the lattice wants a periodic brush-out. [Small Boats Monthly — FIRM; Workshop Heaven ("virtually uncloggable") as the claim it qualifies.] - **Wearing the teeth on metal.** Cutting brass, aluminium or steel spends the edge; reserve it for wood. [Small Boats Monthly.] - **Rust / weld-failure** — no sourced anecdote of either was found; neither is asserted, and both remain gaps. [Flag: Haft, Run 172.] **BEGINNER-TRAP (looks fine until it isn't):** - **The speed surprises you,** including on the fine face; the novice overshoots. [Amazon — SOFT; CLC.] - **Expecting a finish off the fine side.** Etto tested exactly this. [Etto.] - **Scrubbing it like sandpaper.** The saw-type teeth are described as cutting in more than one direction, so it *feels* like you can scrub; control is lost by scrubbing. Use deliberate, controlled strokes in the direction the exact model specifies. [Sawmill Creek — Matthews.] - **Copying an expert's handleless habit.** Buyers expecting a front knob are thrown by the snap-on handle; Schwarz's "skip the handle" was an expert's personal preference, now judged unsafe as general advice. A beginner should not copy it. [Amazon — SOFT; Popular Woodworking.] **LINEAGE-MISUSE (treating it like its ancestor / cousin / namesake):** - **NOT a hand-stitched [[Rasp]].** The surface is categorically cruder. Sellers: the teeth "are not hand stitched and are therefore perhaps too uniform... this harmonic... means that the tool motion you use is more counterproductive than effective." A hand-stitched rasp's randomised teeth finish smoother. [Paul Sellers; corpus: [[Rasp]].] - **NOT a [[File]].** The file is the step after the Shinto; Sellers finishes Shinto work "with a fine, 10″ flat file." [Paul Sellers.] - **NOT a [[Surform]].** Both address the rasp's clog by different geometry (Surform = stamped perforated sheet; Shinto = open saw-blade lattice). In use the Shinto is described as sturdier and faster on hard timber roughing; the Surform as better on green epoxy and structural foam. [WoodenBoat forum — SOFT; Small Boats Monthly; Workshop Heaven; corpus: [[Surform]].] - **NOT a saw — despite being built of saw-toothed strips.** Sellers: "When is a rasp not a rasp? When it's a series of saw blades strategically locked together... nomenclature is everything." It shapes by abrading with many small saw teeth, not by cutting a kerf. [Paul Sellers.] - **Do not read the Japanese name as a lineage claim, and do not read the patents as one either.** The brand does not establish an ancient Japanese tradition, and the earlier U.S. patents are related prior art, not an established Shinto genealogy. (Replaces the original's "NOT a traditional Japanese tool... American patent line," which asserted a chain the evidence does not show.) --- ## correct use **Primary match: untreated wood, rough-to-medium shaping.** *Fast stock removal at the rough-and-medium shaping stage, with a flat face that fairs flat, convex and broad surfaces and a clog-resistant open lattice.* It **cuts effectively with, across and on end grain, but grain direction and edge support still affect the resulting surface.** Small Boats Monthly reports a noticeably smoother surface when worked with the grain than across it. (The original's "grain-indifferent" is withdrawn. Fix 8.) [Small Boats Monthly; Etto Woodworking.] Primary matching, as the reviewer frames it: - untreated wood rough-to-medium shaping; - flat, convex and broad fairing within the exact model's geometry; - rapid removal after sawing and before file, scraper or abrasive finishing where a finished surface is required; - projects where the open lattice's clog resistance is useful. **Nonwood use is conditional, not "verified range."** Retailers and practitioners report the tool working on plywood/chipboard/MDF, plastics, plasterboard, soft stone, modelling clay, structural or surfboard foam, hoof wall, cured epoxy, and brass, aluminium and mild steel. *That a source reports the rasp removing a material is capability, not approval or a safe application.* Treat each as a **conditional specialist match** and see the **material hazard gates** below. These reports rest mostly on retailers (Charnwood material list, Workshop Heaven, CLC) and practitioners (Small Boats Monthly, Etto) and are low-confidence. A maker's approval for the exact model and material was not located for any nonwood material. **Where it sits in the sequence:** a **medium** tool, *after* the bandsaw, jigsaw or turning saw and *before* the file, scraper or sandpaper. Neither face leaves a finish surface. [Popular Woodworking; Paul Sellers; Etto.] **How to use it well (brief — [[Reed]] owns the deep operation):** - **Secure the work.** Clamp or otherwise hold the stock so it cannot move. [Fine Homebuilding; Lee Valley.] - **Use every grip supplied for the selected model,** where the instructions call for it, and keep the other hand clear of the tooth path. **Do not improvise a grip on a replacement blade.** (Replaces the original's categorical "two hands" rule, since the family includes one- and two-grip holders. Fix 9.) - **Controlled strokes in the direction the exact model's instructions specify; let it cut.** Light, steady pressure; do not lean on it. [Charnwood; WoodCentral practitioner ("let it do the work").] - **You needn't skew it.** "Because its teeth aren't aligned in rows you don't have to angle the tool to keep it from getting hung up." [Small Boats Monthly.] - **Coarse face to shape, flip to the fine face to refine, then change tools to finish** — follow with a flat file, scraper or sandpaper. [Paul Sellers; Etto; Popular Woodworking.] - **Clear the lattice with a brush, with the tool secured and hands clear.** The original advised tapping it on the bench (Etto). The review says not to give tapping a sharp toothed lattice on the bench as default cleaning advice without manufacturer support, so it is withdrawn here; use a brush and follow the maker's instructions for cleaning. - **Reserve it for wood** to extend blade life, even where it can cut metal. [Small Boats Monthly.] > **Use flags (honest):** whether it is *especially* good on very hard or dense timber is contested — Etto (burl) and a WoodenBoat thread (purpleheart, Angelique) say excellent; a WoodCentral poster says it "works best on soft material... for hardwood a rasp works much faster and leaves a smoother surface." The defensible synthesis: its teeth survive abrasive stock that dulls ordinary rasps, while finish quality on dense hardwood is where opinions split. Presented both ways, not resolved. --- ## anatomy - **The lattice (the working heart)** — **ten** thin steel **saw-blade strips**, toothed on both edges, arranged in a **cross-hatched diamond pattern** and fixed together to form one open bed. [Lee Valley ("ten individual saw blades joined together in a diamond pattern"); Popular Woodworking ("a series of 10 hacksaw blades that have been bent and riveted together"); Etto Woodworking.] Both broad faces and the exposed edges carry sharp teeth. - **The faces** — reversible: a **coarse face of about 10 tpi** and a **fine face of about 24 tpi** (Lee Valley, Charnwood). "Fine" is relative to the coarse face, not a finish grade. - **The teeth** — saw-type, mill-cut per Cunningham's analysis: vertical front face, straight cutting edge across the top, back sloping directly away. Cunningham contrasts this with the ordinary rasp's "gouged-up" tooth that needs pressure to engage. **Steel: saw-toothed steel; exact alloy and heat treatment are not established in the sources consulted.** (The original called the teeth "hacksaw-hard tempered steel" on Cunningham's inference from trying them on metals; that is not a maker's specification and is withdrawn. Fix 4.) - **Fastening — riveted versus "welded and pinned" (unresolved).** Schwarz (2006) and Cunningham (2015) both say riveted where blades cross; Cunningham notes the sides "curve in a bit at the rivets... (The blades aren't welded where they contact each other)," and that the concavity buries the rivet heads so the rasp can reach into right-angle corners. Several retailers (Charnwood, Workshop Heaven) say "welded and pinned." This is left unresolved for current variants. Do not resolve it from retailer shorthand or from the fastening alternatives disclosed in an old patent (Bryan discloses several). [Popular Woodworking; Small Boats Monthly; Charnwood / Workshop Heaven.] - **Tip / edge geometry** — teeth run to the tip and along the outer edges, so the tool works into corners; the two outermost blades have their edge teeth ground back at a bevel to avoid cutting an unwanted groove in the apex of a corner. [Small Boats Monthly; Fine Homebuilding — Katz, 2007.] - **The holder and handle(s)** — the holder carries the lattice. Models differ: one-handled (SR10, SR20 per the original) and two-handled forms (a rear handle and a front grip, e.g. SR30). On the planer/offset version the handle hooks over the rivets and locks with a screw and is removable, so the blade flips between faces; the blade is **replaceable.** [Lee Valley; Popular Woodworking; Charnwood SR30; Small Boats Monthly.] Lee Valley sells the bare lattice as a **replacement blade for a holder**; that listing does not approve gripping it bare-handed (per the reviewer) `[manual, relayed]`. - **Cut direction — NOT ESTABLISHED for each model.** Charnwood copy and a practitioner (Sawmill Creek, Matthews) describe pushing and saw-type teeth that "cut in either direction"; Bryan's patent describes cutting both forward and backward (per the reviewer). None of these establishes the tooth orientation of a particular current model, and the original's "push stroke" and "cuts in either direction" cannot both stand as instructions. **Use controlled strokes in the direction specified for the exact model; keep both hands on approved grips and out of the tooth path. Do not infer current stroke direction from an older patent or a forum.** `[manual, relayed]` for the reviewer's reading of Bryan. > **Anatomy reading (INTERPRETATION, Haft):** the riveted-versus-welded discrepancy is worth keeping visible. The two woodworkers who looked closest say riveted; retailers say "welded and pinned." The original also noted that the [[Surform]] entry's contemporary-note called the Shinto "welded saw blades," which over-states the welding. [Flag: Haft, Run 172.] --- ## variations (living) - **Standard saw-rasp (inline handle)** — single rear handle in line with the blade; about 9 in and 11 in working faces (e.g. via Japan Woodworker). [Popular Woodworking.] - **Planer-type saw-rasp (offset handle)** — handle raised above the blade plane for flat-surface work; handle removable for face-flip. [Small Boats Monthly; Popular Woodworking.] - **SR10** — about 225 mm (8.9 in) blade, 30 mm wide, 330 mm overall; 10 tpi coarse / 24 tpi fine; single soft-grip handle. [Charnwood SR10.] - **SR20** — intermediate; Charnwood lists a "Double Sided Saw Rasp & File, length 275 mm." [Charnwood — existence FIRM, dimensions SOFT.] - **SR30** — about 255 mm (10 in) blade, 30 mm wide, 380 mm overall; 10 tpi / 24 tpi; **two-handed** (rear handle and front grip), blade locked by a quick-release screw, **replaceable blade** (part SR30F). [Charnwood SR30.] - **Replacement blade (a component, not a tool variant).** Sold bare for fitting to a holder. **It is not a handleless variant.** Use it in its manufacturer-approved handle or holder; protect the teeth during handling and storage. If a current manufacturer expressly approves handleless use, that would need its exact instructions and a stated safe hand placement; none was located. (The original listed "Blade-only (no handle)" as a variant with Schwarz's "skip the handle... save about $10" buy; removed. Fix 1.) - **The two faces** — coarse about 10 tpi (rapid removal, surface not refined) and fine about 24 tpi (smoother, still pre-finish). (Schwarz's 2006 numbers were 11/25; Lee Valley and Charnwood give 10/24, treated as canonical.) [Lee Valley; Charnwood; Paul Sellers; Popular Woodworking.] > **Variation gaps (honest):** no round or rat-tail Shinto in this construction was found; the flat-faced geometry is the central limit. Fisher described curved assembled rasps and Bryan described a flexible variant (per the reviewer), so match against the exact current model's width, stiffness and edge geometry rather than treating concave work as physically impossible for the whole family. Competing brands using the identical lattice were not located beyond the historical objects above. --- ## trades Boatbuilding (stems, rubrails, fairing; epoxy slag and MiniCell foam are conditional and gated above); luthiery (neck, heel and fingerboard-blank roughing — the flat-only limit splits opinion); green-woodworking and chairmaking (roughing hard stock); sculpture and prop/model-making; pattern and general bench woodworking (fairing curves before the file). Farriery and surfboard or structural-foam shaping are reported by retailers and are specialist practice with their own hazards, not casual matches. It is consistently positioned as a roughing-to-medium tool that the user rations and then changes away from to finish. [Sources as cited in *human side* and *correct use*.] **Fields the app should carry** for matching, rather than a single generic label (suggested by the reviewer): exact holder/model, working width and length, coarse/fine tpi, approved stroke direction, replaceable versus fixed blade, material approval, surface geometry, required subsequent finish, and dust or swarf hazard. MDF, plasterboard, stone, epoxy, foam, metals and farriery are **conditional specialist matches,** not equal "correct use" materials. --- ## lineage The Shinto is a **convergence-by-assembly node**: a tool whose teeth are saw teeth and whose body is built up from blades. - **Ancestor (by tooth):** the **saw tooth.** Cunningham reports the teeth are "cut with a mill grinder... identical to how hacksaw blades are made... the front face of each tooth is vertical and the cutting edge across the top is straight, just like the teeth of a ripsaw." [Small Boats Monthly — Cunningham, Nov 2015.] "Mill-cut" comes from Cunningham's "evidently"-qualified analysis; keep that qualifier. "Hacksaw blade" is a useful visual analogy: the sources establish saw blades and saw-like teeth, not a standard hacksaw blade specification. - **Ancestors (by job):** the **[[Rasp]]** and the **[[File]]**, the toothed-steel hand abraders it competes with and is shelved beside. - **Related prior art (NOT a proven ancestor).** Earlier U.S. patents document assembled saw-tooth rasps: **Isaac Fisher, US 76,618 (St. Louis, April 14, 1868),** a rasp of thin serrated steel blades bolted together; **George Hare, US 2,059,945 (1936),** a "Hand Meat Block Planer" of parallel toothed strips (cited as prior art by Bryan's patent, per the original run's reading of Google Patents); and **Carroll W. Bryan, US 2,549,570 (filed 1946, granted 1951),** a close non-parallel multi-saw surfacing tool. See *history*. Current Shinto saw-rasps are made in Japan. **No direct corporate, licensing or manufacturing link between these patents and the Shinto-branded product was found.** - **Descendants:** none distinct in the corpus. Other-branded saw-blade lattice rasps reported by Vintage Tool Patch — the "Marvel" (C.J. Anderson) and the 1950s Japanese-made "Globe Master Surf Rasp" — are photographed objects, undated and soft. [Vintage Tool Patch — SOFT.] - **Contemporaries (similar job, different mechanism):** the hand-stitched **[[Rasp]]**, the **[[File]]** (the finishing step *after* the Shinto), the **[[Surform]]** (the other anti-clog answer — stamped perforated sheet), the **[[Microplane]]**, the **[[Riffler]]** and **[[Float]]**. > **Lineage reading (INTERPRETATION, Haft):** the Shinto sits inside the abrading family's wall as a toothed-steel hand abrader. It adds a fifth tooth-forming label to the tree's four (CUT, PUNCHED, PERFORATED, ETCHED): **ASSEMBLED** — the tooth is a saw tooth borrowed from saw-blade stock and the rasp is built up from ten of them. (TREE NOTE: the next refresh of the [[_Abrading Family — Lineage Tree]] should judge whether this joins the manufacturing axis; the original placement relied on the 1951 Bryan date as a Shinto root, which this correction withdraws, so the placement should be re-judged from the tool's own evidence.) --- ## history **What is established.** Current Shinto saw-rasps are made in Japan; "made in Japan" is well supported by current retail catalogues. "Shinto Industrial Co., Ltd." appears in specialist-retailer information; the original run also found a German retailer (Schilbach) giving the maker as "Shinto Kogyo Co.," Miki City, Hyōgo, a traditional Japanese hub for files, rasps and saws. A manufacturer-primary corporate history and founding date were not found, so the corporate identity is soft. [Lee Valley; Charnwood; Schilbach — "made in Japan" FIRM; corporate identity SOFT.] **Related U.S. prior art (patent facts as relayed from the reviewer's reading of the primary documents):** - **US 76,618 — Isaac Fisher, St. Louis, April 14, 1868.** A rasp made of thin steel blades with one or both edges serrated, held together by screw bolts; alternate blades can slide to align teeth for sharpening and be reset for rasping; flat and curved configurations are described. It is not the same cross-hatched lattice as the current Shinto. Treat it as **early prior art for assembled saw-tooth rasps, not a proven ancestor of the Shinto product.** `[manual, relayed]` - **US 2,059,945 — George Hare, "Hand Meat Block Planer," 1936.** Per the original run: "an elongated body composed of a plurality of parallel strips... knife blades... teeth provided on the working edges," classified B27G17/06 (woodworking rasps); cited by Bryan's patent. The review notes Bryan's patent lists Hare's patent among its U.S. references. `[manual, relayed]` - **US 2,549,570 — Carroll W. Bryan of Dallas, "Surface conditioning tool,"** filed April 9, 1946, granted April 17, 1951. Per the reviewer's reading of the primary text: a **non-parallel gang of saw blades, alternate tooth directions, open debris spaces, replaceable handles and several alternative fastening methods;** the preferred device can flex over non-flat surfaces and the patent describes cutting both forward and backward. It claims a surface-conditioning tool, not the Shinto brand. Call it **a close patented precursor/analogue to the current lattice saw-rasp form.** It does not mention Shinto, Japan, a licence, or a current maker. `[manual, relayed]` (The original run also recorded S. Austin Wier as assignee.) **The origin hypothesis, kept separate.** The tool historian Vintage Tool Patch (seanodonnell, 2022) traced a patent chain and wrote that Bryan's patent "is the first 'Shinto Rasp'," concluding the Shinto is "a Texan rather than Japanese tool." The author frames this as "I believe" and acknowledges "You could argue the toss" (per the reviewer). **That is a hobbyist historian's research lead, not a documented product genealogy.** Nothing found establishes a corporate, licensing or manufacturing chain from Bryan to the Japanese product. The original entry's "The Shinto is a Texan tool," "American patent roots" and "merely manufactured in Japan" are withdrawn. The convergence point stands: assembled saw-tooth rasps predate the current Shinto product. Where and by whom the current two-sided diamond-lattice model was first commercialized is not established. > **History reading (INTERPRETATION, Haft, revised):** the original framed the Shinto as the mirror of the Surform's "American brand, British patent" origin correction. That framing is withdrawn because it depended on a lineage the evidence has not shown. What survives is smaller and safer: the Japanese brand does not imply an ancient Japanese tradition, and related U.S. patents show the mechanism had earlier non-Japanese examples. Henry Petroski is not on record naming this tool; the form-follows-failure framework applies but is not attributed to him. **The Petroski lens — form follows failure.** The failure is **clogging**: a rasp or file packs with the material it removes, worst on green, resinous or gummy stock. The Surform's answer was a hole through every tooth. The open, non-parallel lattice of the Shinto gives debris escape space and resists clogging; this is supported by current product descriptions and by Bryan's patent (open spaces). Cunningham additionally argues that breaking teeth out of continuous rows reduces packing: *"It's easy to push one person off a chair; difficult to shove a row of congregants off a pew. The vast majority of the teeth on the Shinto are loners."* **Treat that as practitioner analysis, not a manufacturer test or comparative engineering study.** [Small Boats Monthly — Cunningham, 2015.] --- ## ✦ human side The Shinto belongs to the working trades more than to the fine-furniture bench. - **Boatbuilders — the trade most at home with it.** Chesapeake Light Craft (CLC) calls it "a must-have tool in the art of boatbuilding," using it for rubrails, stem and stern profiles, rough-shaping MiniCell foam seats and knocking down cured epoxy slag; the coarse side gives "chainsaw-like removal of material." [CLC Boats product page — a retailer's description; for epoxy and foam see the hazard gates below.] Christopher **Cunningham** (editor, *Small Boats Monthly*) has used his Planer Saw Rasp "at least a decade, maybe 15 years" — rounding oak dory stems, fairing spruce tenons for Greenland kayaks. [Small Boats Monthly, 2015.] - **Luthiers — a real split, and a datum.** Some use it on dense exotic neck and fingerboard-blank work. But **Tom Bills** (professional luthier, author of *The Art of Lutherie*) reaches past it for a hand-cut rasp: the Shinto "is an amazing and unique tool that works really well," but "the fact that it can be used only to carve a flat surface is very limiting for my purposes." [The Art of Lutherie.] - **Farriers (specialist practice, not a casual match).** Workshop Heaven (UK): "our local farriers swear by them for filing horses' hooves." [Workshop Heaven product page — a retailer's claim.] - **Others.** Paul Sellers: "Whether you are making a canoe or kayak or a new surfboard, or refining the neck of a guitar or cello, this Shinto thingy will take you pretty much all the way." [Paul Sellers, 2019.] On Sawmill Creek, chairmakers weigh it for roughing hard jarrah backrests (a spokeshave or drawknife beats it there; the Shinto is good for the initial hog). [Sawmill Creek, 2014.] - **The named hands who put it on the Western map.** **Christopher Schwarz** (then *Popular Woodworking*) wrote the 2006 post that introduced it to many US hand-tool woodworkers after watching Glen Huey use one on cabriole legs. Schwarz's piece also gave the buying advice to skip the handle and buy the blade alone. **That is his personal preference as a source author; it is not a manufacturer-approved use and this entry does not repeat it as advice** (see Fix 1). **Paul Sellers** reviewed it in 2019: "a definite positive buy," below a fine hand-stitched rasp but above a cheap machine-stitched one. **Gerald Etto** found it cut Malaysian burl in "about ¼ of the time" of a regular rasp. [Popular Woodworking, 2006; Paul Sellers, 2019; Etto Woodworking, 2020.] - **The culture — the "guilty pleasure."** A LumberJocks thread is titled *"Shinto... My guilty pleasure. Dirty little secret"* (title only, via search; SOFT). Sellers, plainly: *"The Shinto rasp justifies the title ugly. It's not a pretty thing like a well made and finely tuned rasp so let's not pretend."* Schwarz, recanting his first impression: *"It looked so unfamiliar to me — not a rasp, not a saw — that I never had the urge to try it."* [Popular Woodworking, 2006.] It is also the family's cheapest serious tool, roughly 15-20% of the price of a premium hand-stitched rasp. [Popular Woodworking; retail.] *(The original's "name irony" passage, a Shinto-shrine nail-free construction story offered as texture, has been removed. It rested on one author's recollection of a professor, and the reviewer found the cited material does not establish the claimed prohibition or explain the brand name; museum collections document Shinto shrine objects with metal fittings, e.g. the British Museum household shrine. See Fix 11.)* --- ## ✦ proof of existence **The current tool is catalogue-anchored; the related designs are patent-anchored.** No museum accession was found for the Shinto product (consistent with a 20th-century commodity hand tool). - **Current product:** Lee Valley's catalogue (per the reviewer) supports ten saw blades in a diamond pattern, 10/24 tpi reversible faces, an open clog-resistant structure, two handles, made-in-Japan status and a separately sold replacement blade. Also sold by Charnwood ("Asahi Quality Japanese Carpentry Tools"), CLC, Workshop Heaven, Fine-Tools and Rockler (which also sells replacement blades). The living tool is firm; the corporate identity is soft. `[manual, relayed]` for Lee Valley's content. - **Related patent prior art:** **US 76,618,** Isaac Fisher, St. Louis, April 14, 1868 (bolted serrated-blade rasp; details as relayed from the reviewer's reading of the primary PDF); **US 2,059,945,** George Hare, 1936 (per the original run); **US 2,549,570,** Carroll W. Bryan of Dallas, filed April 9, 1946, granted April 17, 1951 (non-parallel gang of saw blades; details as relayed from the reviewer). The Fisher and Bryan primary texts were read by the reviewer, so their existence and mechanism are firm; the "1951" is the grant date, the design was filed in 1946. `[manual, relayed]` - **What the patents do not prove:** none names Shinto, a Japanese maker, a licence, a current assignee in the product chain, or a transfer to Japan. They prove earlier American examples of the mechanism, not a direct lineage for the Shinto-branded product. - **Parallel forms (objects, undated/soft):** "The Marvel" (C.J. Anderson Mfg., Chicago — undated) and the 1950s "Globe Master Surf Rasp" made in Japan and sold under a US brand, both photographed by Vintage Tool Patch. [Vintage Tool Patch — SOFT.] > **Proof reading (INTERPRETATION, Haft, revised):** firm on the current product and on the existence and mechanism of the Fisher and Bryan patents (read by the reviewer in the primary documents), soft on direct genealogy, soft on corporate identity, absent on any museum record. The Fisher patent is upgraded from the original's soft lead to a firm primary fact about the mechanism, classed as early prior art and not as an ancestor. --- ## references URLs as in the original run and in the reviewer's 2026-07-27 Source Notes. None were re-fetched in this pass; entries tied to the reviewer's description of a source are marked `[manual, relayed]`. - Christopher Cunningham, "Shinto Rasps," *Small Boats Monthly* (WoodenBoat), Nov 2015 (close tooth/rivet analysis; the "loners not rows" argument; practitioner observations about rivets, clog points, tooth geometry, metal-cutting, corner access and smoother results with the grain; presents close analysis, not manufacturer specifications for steel temper or approved materials). https://smallboatsmonthly.com/article/shinto-rasps/ — kind: trade publication - Christopher Schwarz, "The Venerable and Inscrutable Shinto Rasp," *Popular Woodworking*, 2006 (riveted ten-blade construction; coarse/medium/fine framing; the author's handleless preference — not a manufacturer-approved use; also contains an unsupported Shinto/kami/nail cultural story, not carried). https://www.popularwoodworking.com/techniques/the-venerable-and-inscrutable-shinto-rasp/ — kind: trade publication - Paul Sellers, "The Shinto Rasp," *Paul Sellers' Blog*, July 2019. https://paulsellers.com/2019/07/the-shinto-rasp/ — kind: blog (master craftsman) - US 2,549,570 — "Surface conditioning tool," Carroll W. Bryan (of Dallas), filed 1946, granted 1951. https://patents.google.com/patent/US2549570A/en — kind: patent `[manual, relayed]` - US 76,618 — Isaac Fisher (St. Louis), April 14, 1868. https://patentimages.storage.googleapis.com/c6/a2/59/0c74051170269f/US76618.pdf — kind: patent (primary PDF, read by the reviewer) `[manual, relayed]` - US 2,059,945 — "Hand Meat Block Planer," George Hare, 1936 (cited by US 2,549,570; per the original run). https://patents.google.com/patent/US2059945 — kind: patent - seanodonnell, "The Texan Shinto Rasp," *Vintage Tool Patch*, May 2022 (the source of the direct Bryan-to-Shinto identification; the author frames it as "I believe" and acknowledges it is arguable). https://blog.vintagetoolpatch.com/2022/05/08/shinto.html — kind: blog (tool historian) — origin hypothesis only - Lee Valley — "Japanese Saw Rasp" (ten saw blades in a diamond pattern; 10/24 tpi reversible faces; open structure; two handles; made in Japan; separately sold replacement blade; does not approve gripping the replacement blade bare-handed). https://www.leevalley.com/en-ca/shop/tools/hand-tools/files-and-rasps/rasps/65692-japanese-saw-rasp — kind: manufacturer/retailer `[manual, relayed]` - Charnwood — Shinto SR10 / SR30 product pages (spec tables; "welded and pinned"; replaceable blade; "Asahi" brand line). https://charnwood.net/product/shinto-sr10-japanese-saw-rasp/ ; https://charnwood.net/product/shinto-sr30-japanese-saw-rasp/ — kind: retailer - Workshop Heaven — Shinto Saw Rasp ("very sharp" warning; farriers; "virtually uncloggable"). https://workshopheaven.com/shinto-saw-rasp/ — kind: retailer - Chesapeake Light Craft — Shinto Saw Rasp. https://clcboats.com/products/shinto-saw-rasp — kind: retailer (trade shop) - Gary Katz, "Saw Rasp Review," *Fine Homebuilding*, Nov 2007. https://www.finehomebuilding.com/2007/11/20/saw-rasp-review — kind: trade publication - Tom Bills, "Choosing a Wood Rasp," *The Art of Lutherie*, 2022. https://theartoflutherie.com/wood-rasp/ — kind: blog (professional luthier) - Gerald Etto, "Shinto Rasp Review," *Etto Woodworking*, 2020. https://ettowoodworking.com/shinto-rasp-review/ — kind: blog (hobbyist) - Sawmill Creek — "Shinto rasp info wanted," 2014; WoodCentral — same thread/title, 2014. https://sawmillcreek.org/threads/shinto-rasp-info-wanted.214265/ ; https://www.woodcentral.com/forums/topic/3472034/ — kind: forum (lower confidence) - IARC Monograph Vol. 62, *Wood Dust and Formaldehyde* (1995) — occupational wood dust carcinogenic to humans (Group 1). https://publications.iarc.who.int/80 — kind: scientific/regulatory (does not supply a complete hazard plan for nonwood materials) - HSE, MDF guidance (wood dust, possible formaldehyde/resin-related exposure, local exhaust, HEPA vacuum). https://www.hse.gov.uk/woodworking/faqs.htm — kind: regulatory `[manual, relayed]` - NIOSH, "Drywall Sanding — Hand Sanding" (high total/respirable dust, possible silica from joint compound; vacuum-control systems). https://www.cdc.gov/niosh/engcontrols/ecd/detail32.html — kind: regulatory `[manual, relayed]` - WEST SYSTEM, "Preventing Overexposure" (ventilation and suitable respiratory protection when sanding epoxy, especially partially cured; sensitization). https://www.westsystem.com/safety/preventing-overexposure/ — kind: manufacturer safety `[manual, relayed]` - British Museum, household Shinto shrine (wooden shrine object with metal fittings; cited by the reviewer as the reason the "no metal" claim is not repeated). https://www.britishmuseum.org/collection/object/A_OA-7195 — kind: museum collection `[manual, relayed]` - OSHA Wood Dust hazard page (from the original run; not re-read). https://www.osha.gov/wood-dust/hazards — kind: regulatory ## Forge images this entry will need 1. **"A rasp made of saws"** — a clean macro of the ten-blade diamond lattice, one blade pulled out to show it is a toothed saw-blade strip. The single image that explains the tool. (Priority.) Draw it in its holder. 2. **"Two cures for one clog"** — the [[Surform]] beside the Shinto: Surform = chip exits through a punched hole; Shinto = open, non-parallel lattice leaves space for debris. Caption the "loners not rows" argument as Cunningham's analysis. 3. **"Five ways to make a tooth"** — extend the CUT/PUNCHED/PERFORATED/ETCHED quartet to a quintet by adding the Shinto's **ASSEMBLED** tooth: [[File]] cut ridge · [[Rasp]] punched point · [[Surform]] perforated rim · [[Microplane]] etched edge · Shinto saw-tooth assembled from blades. 4. **"Related prior art, not a family tree"** — a light plate: the Shinto product beside the Fisher 1868 and Bryan 1946 patent drawings, captioned "earlier U.S. patents document related assembled saw-tooth rasps; no direct link to the Shinto product found." (Replaces the original's "Japanese name, Texan patent" plate.) --- *Corrected copy. Next lean: have the reviewer re-check blind; fetch the maker's instructions for each current model to settle stroke direction, fastening and handle approval; decide separately whether farriery or nonwood specialist use belongs in the corpus at all. — Tooick's fix desk, 2026-10-16* ## The reviewer's corrections (12) - `BLOCKER` — 1. Do not recommend the replacement blade as a handleless tool — Exact claim: “**Blade-only (no handle)** — sold bare; Schwarz's recommended buy,” paired with “skip the handle” buying advice and the admission that there is “**No safe back when you grip a bare blade**.” - `BLOCKER` — 2. Add material-specific hazard gates or narrow the material list — Exact claim: “Verified material range” includes “plywood/chipboard/MDF, plastics, plasterboard, soft stone, modelling clay, surfboard/structural foam, horse hoof wall” and cured epoxy, brass, aluminium and mild steel, while safety gives only “Wood dust — IARC Group 1.” - `BLOCKER` — 3. Resolve the push-only versus bidirectional-cut contradiction — Exact claim: “**Push stroke; let it cut**” and “cuts on the **push stroke**,” but also “the saw-type teeth **cut in either direction**” and encourage flipping/using a bare blade. - `BLOCKER` — 4. Separate capability from approval for metal, stone, plaster and composites — Exact claim: “The teeth are **hacksaw-hard tempered steel** — they cut brass, aluminium, and even mild steel,” and the “correct use” section calls the broad material range verified, then says to reserve the tool for wood. - `SHOULD-FIX` — 5. Do not turn patent similarity into direct Shinto lineage — Exact claim: “its patent line runs ... through a Dallas inventor,” “the design's patent lineage is American,” and “it is in fact a 20th-century industrial product with American patent roots ... merely MANUFACTURED in Japan.” - `SHOULD-FIX` — 6. Correct and strengthen the Fisher patent description — Exact claim: “US 76,618 ... a saw-blade rasp patent ... ~1860s,” carried merely as a lead not directly fetched. - `SHOULD-FIX` — 7. Use the Bryan patent precisely — Exact claim: Bryan's patent is presented as the “earliest dated record of the modern tool” and proof that the Shinto is Texan. - `SHOULD-FIX` — 8. Remove “grain-indifferent” — Exact claim: “fast, **grain-indifferent**, low-clog stock removal.” - `SHOULD-FIX` — 9. Make workholding and hand use variant-specific — Exact claim: “**Two hands, work clamped. It is meant for two-handed control**,” while listing one-handled SR10/SR20 forms and handleless use. - `SHOULD-FIX` — 10. Qualify the anti-clog mechanism — Exact claim: It solves clogging “because its teeth are scattered, not arranged in rows,” and “un-rowing the teeth” is the opposite geometric cure to Surform perforations. - `SHOULD-FIX` — 11. Remove the unsupported Shinto-religion construction story — Exact claim: A Shinto shrine “wouldn't use any nails or metal ... because that would be offensive to the kami (or spirit) of the tree,” used as the “name irony.” - `MINOR` — 12. Lower the overall confidence grade — Exact claim: “base: **HIGH**” and “effective: **HIGH**.”