Hand File Guide

A hand file is a hardened steel tool with rows of cutting teeth used to shape, deburr, smooth or fit metal and other workshop materials by hand. The right file for any job is determined by four decisions: cut grade (bastard / second cut / smooth), tooth pattern (single cut / double cut / rasp), shape (flat / round / half-round / three-square / square / mill / knife / warding / needle), and material compatibility — because file teeth at roughly Rockwell C 62-66 cannot cut anything harder than themselves. This guide covers all four selection axes, the AU OHS tang handle rule, draw filing technique, the pinning problem and the forum-tested ways to fix it, plus the P&N + Pferd + Sutton + Eze-Lap range stocked at AIMS.

AIMS Industrial stocks the full files and file sets range — 148+ active SKUs across the Australian-made P&N range, German-engineered Pferd, Sutton Tools needle files and Eze-Lap diamond specialty files — plus file handles for the mandatory tang fitting. Contact the AIMS team or call (02) 9773 0122 for technical selection advice or bulk supply.

A single cut file has one set of parallel teeth angled across the face, while a double cut file has two sets of teeth crossing each other at angles, creating a diamond pattern. Single cut files remove less material per stroke and leave a smoother finish — used for sharpening, draw-filing, finishing soft metals, and final passes. Double cut files remove material much faster but leave a coarser finish — used for stock removal, rough shaping, and working hard metals. As a rule: use double cut for fast removal, then switch to single cut to clean up the surface.

Single Cut vs Double Cut Files — Quick Reference

File coarseness (rough, bastard, second cut, smooth, dead smooth) is a separate spec from single/double cut and applies to both types — match coarseness to the precision required.

What is a hand file?

A hand file is a hardened high-carbon steel tool body with parallel rows of cut teeth running across its working faces, used by hand to remove material in a controlled, repeatable way. The file body is heat-treated to approximately Rockwell C 62-66 hardness — harder than most workshop steels (mild steel sits at Rc 15-25, mild tool steel around Rc 25-30) so the teeth cut on the forward stroke. Anything harder than the file body itself cannot be filed and must be ground, lapped or cut with diamond abrasive.

The four selection decisions for any filing job:

1. Cut grade — rough / bastard / second cut / smooth / dead smooth — controls material removal rate vs surface finish.
2. Tooth pattern — single cut (one direction of teeth) or double cut (two crossed directions) — controls aggression and finish.
3. Shape — flat / round / half-round / three-square / square / mill / knife-edge / warding / needle — matched to the workpiece geometry.
4. Material compatibility — covered in detail below — what the file is designed to cut vs what will damage it.

This guide covers tool files — not digital file types

If you're looking for information on document file types (PDF, DOCX, JPG, MP3) or database file formats (CSV, JSON, SQL flat file), you're in the wrong place. This guide covers hand-operated cutting tools — the metal and woodworking files used in workshops, on chainsaws, and in fabrication shops.

For the avoidance of doubt: a "file" in workshop terminology is a piece of hardened steel with teeth. A "flat file" in a workshop is a rectangular cross-section hand file used for general filing — not a database without table relationships. The two share no overlap.

File cuts decoded — rough, bastard, second cut, smooth, dead smooth

The cut grade controls how much material the file removes per stroke and how smooth a surface it leaves. The standard grades from coarsest to finest:

The practical workshop progression: bastard cut for rough stock removal, second cut for general shaping and fitting, smooth for final finish. The progression matches sandpaper grit selection — same logic of coarse-to-fine in stages. For abrasive paper selection see the Sandpaper Grit Guide.

Forum-validated rule of thumb from Practical Machinist and Hobby-Machinist threads: most workshop filing is done with second cut. Bastard for rapid removal, smooth for finish. Dead smooth and rough are specialty grades most workshops never need.

Single cut vs double cut tooth patterns

File teeth are cut in two patterns. The choice between them affects cutting speed, finish quality and what materials the file is best suited to.

The single-cut-for-soft-metals rule: double-cut files clog (pin) very quickly on soft metals like aluminium and brass. Single-cut files have wider gullets between teeth and clear more readily. This is why mill files for saw sharpening are single cut and why bodywork files for aluminium panel work are curved tooth.

The eight common file shapes — and what they do

Specialty shapes also stocked at AIMS:

• Cabinet rasp / wood rasp — coarse rasp cut on a half-round body for shaping wood. P&N Half-Round Cabinet Rasp.
• Chainsaw file — round file in specific diameters matched to chainsaw chain pitch. P&N Chainsaw File (1/8, 5/32, 3/16, 7/32, 1/4 sizes) + Pferd Chain Saw File.
• Needle files — small files (typically 140-160mm overall, 50-70mm cutting length) for fine work, jewellery, watch repair, model making, instrument repair. Sutton M305 T001 Needle Files in 12 profiles (Barret, Crochet, Crossing, Half Round, Knife Edge, etc.) + Eze-Lap Diamond Needle + Pferd Diamond Needle.

File materials guide — which file for which workpiece

The file hardness rule is absolute: file body is roughly Rockwell C 62-66 — you cannot file anything harder than that. Hardened tool steel, case-hardened parts, hardened bearing races, carbide and ceramic are all harder than file teeth and will simply skate or chip the teeth. For materials above file hardness, use a grinder, abrasive wheel or diamond tool.

The aluminium pinning problem deserves a special note. Aluminium is soft enough to file easily but ductile enough to weld itself into file gullets after a few strokes. Once pinned, the file is dragging compressed aluminium across the workpiece — scratching, not cutting. Three workshop fixes (all forum-validated):

1. Chalk the file before use — rub blackboard or railroad chalk firmly along the file faces in the direction of the teeth. The chalk fills the gullets, prevents aluminium adhesion, and is wiped clean with a brass brush at the end of the job.
2. Use a single-cut or curved-tooth aluminium-specific file — the wider gullets and milled tooth profile resist pinning. Bodywork files used in panel beating are this style.
3. Frequent file-card cleaning — pull a file card along the file faces in the direction of the teeth (not perpendicular) every few minutes during aluminium work.

Hand files vs needle files vs rasps

Three families of hand-operated cutting tools share the "file" name but have distinct applications.

Hand files are the general workshop tool — 150-350mm overall length, tang at one end for the handle, body with cut teeth, typically used with two hands (handle hand pushes, other hand stabilises the tip). The workshop default for metalwork. P&N and Pferd both stock the full size range across all shapes.

Needle files are smaller (typically 140-160mm overall, with 50-70mm cutting length and 60-80mm handle integrated into the body), used for fine detailed work — jewellery making, watch repair, model engineering, instrument repair, fine fitting. Sutton M305 T001 series covers 12 profiles in AU industrial supply. Eze-Lap and Pferd diamond needle files extend the range to harder materials.

Rasps are not technically files — they have individual triangular teeth raised from the body surface rather than cut rows. The aggressive tooth profile suits soft, fibrous or pliable materials — wood, leather, plastic, plaster, soft metals. Cabinet rasps in half-round profile are the common form. P&N Half-Round Cabinet Rasp.

File sizes and how to choose

Hand file sizing refers to the length of the cut portion of the body — not the overall length including tang. AU industrial supply standard sizes are 100, 150, 200, 250, 300, and 350mm.

The starting set for a general workshop: 200mm flat second-cut, 200mm half-round second-cut, 250mm flat bastard, 200mm round second-cut, plus a 200mm three-square second-cut. Five files cover 80%+ of workshop filing tasks. Add needle files only when fine detail work justifies them.

⚠️ The tang handle rule — AU workplace safety requirement

AIMS stocks the matching file handle range separately. Standard timber + brass ferrule handles in 100, 125, and 150mm sizes, sized to fit the tang. Pferd also offers files with pre-fitted handles — see the Pferd Hand File With Handle and Pferd Flat File With Handle range.

Other file safety basics:

• Eye protection mandatory — safety glasses at minimum. File teeth occasionally break off; workpiece swarf flies.
• Never use a file as a pry bar, chisel, or hammer. The hardened brittle body shatters. Documented workshop injury source.
• Don't strike one file against another — both can chip.
• Store files separated — don't pile them together. Tooth-on-tooth contact dulls teeth quickly.

How to use a file properly — pressure, stroke direction, draw filing

Three technique principles separate efficient filing from worn-out files and rough finishes:

1. Pressure on the forward stroke only. File teeth are oriented to cut on the push. Apply firm downward pressure on the forward stroke; on the return stroke, lift the file off the work or maintain only token contact. Dragging a file backward with pressure dulls the teeth rapidly. This is consistent across every workshop reference — Practical Machinist forum, AU OHS guidance, machinist training texts — and explains why factory-new files lose their cut surprisingly fast when used carelessly.

2. Long smooth strokes, not short choppy ones. Use the full length of the file in each stroke. Short rapid strokes cause workpiece chatter, uneven cut, and rocking that produces a convex (rather than flat) surface. The forum consensus on Hobby-Machinist and Practical Machinist: aim for one steady stroke per second, full file length, controlled pressure.

3. Draw filing for surface finish. When you need a truly flat smooth surface — fitting a precision joint, finishing a machined face, achieving a polished edge — turn the file 90° to the workpiece and pull it lengthwise along the work like a scraper, gripping near each end. The teeth then cut across the workpiece axis and produce a much finer scratch pattern than push filing. A smooth or dead smooth cut file used in this technique produces near-machined surface quality.

Holding the file: Push handle with the dominant hand, stabilise the tip with the other hand. For heavy stock removal, both hands stay on the file throughout. For finishing work, the tip hand provides direction control. For fitting small parts in a vice, single-hand operation works for short strokes.

Pinning — the #1 file failure mode

Pinning is the workshop term for when small particles of the workpiece material wedge between file teeth, blocking the cutting action and turning the file from a cutter into a polished metal block that scratches rather than removes. Pinned files cut slowly, leave deep scratches in the workpiece, and feel "tired" under the hand.

Prevention — workshop-tested techniques:

• Chalk the file before use on pinning-prone materials — aluminium, cast iron, brass, copper. Rub blackboard chalk or railroad chalk firmly along the file faces in the direction of the teeth. Chalk fills the gullets, prevents adhesion, comes off with a brass brush at job end. Forum-validated technique from Practical Machinist threads.
• Use single-cut or curved-tooth files for soft metals — wider gullets clear better.
• Brush the file frequently during pinning-prone work — every few strokes for aluminium and cast iron.
• Apply moderate pressure — too much pressure on soft materials accelerates pinning.

Removing pinning — when prevention failed:

• File card — a stiff wire brush with bristles oriented to comb out the gullets. Draw the card across the file faces in the direction of the teeth, not perpendicular. Wrong direction (across the teeth) bends the teeth and ruins the file. This is the #1 forum-flagged mistake — file cards are misused regularly.
• Wood block — a hand-sized block of pine or fir with a square-cut end, rubbed firmly across the file teeth. The wood compresses into the gullets, picks up the pin material, and clears it. Oak works for stubborn pins. Slower than a file card but won't damage teeth even if used wrong.
• Penny edge (forum-validated trick) — the soft copper edge of a coin (an AU 1c or 2c coin or any soft copper-alloy disc) cuts its own profile into the file teeth and removes pinning without damage. The coin sacrifices itself; the file stays intact. Effective for targeted spot cleaning.

Chainsaw files — sizing by chain pitch

Chainsaw cutters require a round file matched precisely to the chain pitch. Wrong size = wrong cutting angle = chain that won't cut straight, dulls quickly, or cuts dangerously. The relationship:

Always check the chain manufacturer's spec stamped on the chain or in the saw manual. Don't guess. AIMS stocks the full chainsaw file range: P&N Chainsaw File in 1/8, 5/32, 3/16, 7/32, 1/4 sizes, and the Pferd Chain Saw File range including premium 4.0mm and 4.5mm variants.

Australian brand guide — P&N, Pferd, Sutton, Eze-Lap

P&N is the Australian-manufacturer story — same patriot positioning as Macnaught grease guns and Linishall wire wheels. AU-made, in-stock at industrial supplier depth, full range coverage. Pferd is the German-engineered premium tier — "the best" per Practical Machinist forum consensus, sharp longer than mass-market alternatives, full with-handle and no-handle range. Sutton needle files cover specialty profiles for jewellery, watch repair, model engineering. Eze-Lap diamond needle files extend the range to hardened tool steel and tungsten carbide where standard files cannot cut.

Forum consensus across Practical Machinist and Hobby-Machinist threads on brand quality: Grobet (Swiss) cuts "more nicely," Pferd "the best" for industrial work, Simonds well-regarded for US-made, Nicholson quality has degraded with Mexico/Brazil manufacture (the consensus complaint). P&N covers the AU-industry-standard tier for general workshop work.

AIMS-stocked range deep dive

148+ active file SKUs plus 7 file handle products. Top picks across the four selection axes:

For the complete inventory across all 148+ SKUs, browse the Files & File Sets collection or the broader Files & Chisels parent collection.

File vs other deburring and shaping tools

For controlled chamfer on drilled hole edges, slots, and small-part edge breaking, the swivel-blade deburring tool is usually faster and more uniform than a file — see the Deburring Tool Guide for blade types (Shaviv B/E series, Noga S series, Bordo NB/SE series), the clockwise rotation rule, and the "wrist slitter" safety warning machinists should know about.

Files are one option among several for material removal and finishing. The right tool depends on the job geometry, removal rate required, and surface finish target.

The practical workshop combination: grinder or flap disc for rough stock removal → file for controlled shaping and edge breaking → smooth file or draw filing for finish → abrasive paper for polish. Each tool fills a different position in the coarse-to-fine progression.

Common file mistakes

Selection checklist

1. What material? Use the materials table above. If Rc 55+ → grinder, not file.
2. Stock removal or finish? Bastard for stock removal, second cut for general, smooth for finish.
3. Soft metal (aluminium, brass, copper)? Single cut + chalk, or curved-tooth aluminium file.
4. Wood, plastic or soft material? Rasp, not file.
5. Shape match to workpiece geometry? Flat for flat; half-round for the all-purpose default; round for holes; three-square for angles under 60°; square for keyways.
6. Size? 200-250mm covers most workshop work. 300mm for heavy removal. 150mm for tight access. Needle files for fine work only.
7. Handle fitted? Always. Non-negotiable AU OHS rule.
8. Chainsaw chain? Round file matched to chain pitch — check manufacturer spec.
9. Brand? P&N for AU-made volume tier; Pferd for German-engineered premium; Sutton for needle files; Eze-Lap for diamond on hardened materials.

For full range, technical advice, or workshop bulk supply, contact the AIMS team or call (02) 9773 0122. Adjacent guides: Hammer Types, Wire Brush & Wire Wheel Guide, Bench Grinder Guide, Angle Grinder Guide, Sandpaper Grit Guide, Stick Welding Guide (file work in slag dressing).

Frequently Asked Questions

What's the difference between bastard, second cut and smooth files?

Cut grades are file tooth coarseness — bastard is coarsest of the workshop grades (25-30 teeth/inch, rapid stock removal, rough finish), second cut is medium (30-40 teeth/inch, general workshop default), smooth is fine (40-55 teeth/inch, finish work). Rough is even coarser than bastard but rarely used; dead smooth is finer than smooth. Workshop progression: bastard for stock removal → second cut for shaping → smooth for finish.

What is "double cut" and "single cut" on a file?

Single cut files have one row of parallel teeth at an angle to the file axis — slower removal, smoother finish, preferred for soft metals (brass, aluminium) and saw sharpening. Double cut files have two crossed rows of teeth (typically 45° + 35°) — faster removal, rougher finish, the standard for general steel and cast iron filing. Rasps are a third pattern with individual triangular teeth — for wood and soft material.

Why do I need a handle on a file?

AU workplace safety requirement (WorkSafe Tas, SafeWork SA and equivalent state OHS) — files without handles are workplace injury hazards. The tang is soft and bends; the file body is hardened and brittle. If the file binds during a push stroke and slips, the exposed tang can stab into the user's palm. Documented injury source. Files come unhandled because workshop convention is to fit the handle on first use, not because they're intended for unhandled use.

What is draw filing?

Draw filing is a technique for producing smooth, flat surfaces. Turn the file 90° to the workpiece (perpendicular to the normal push-filing direction), grip near each end of the file, and pull it lengthwise along the work like a scraper. The teeth then cut across the workpiece axis and produce a much finer scratch pattern than standard push filing. A smooth or dead smooth cut file used in draw filing produces near-machined surface quality. The technique is universal across machinist and toolmaker training.

What is pinning and how do I prevent it?

Pinning is when small workpiece particles wedge between file teeth, blocking cutting action — common with aluminium, brass, copper and cast iron. Prevention: rub blackboard chalk firmly along the file faces before use (the chalk fills the gullets and prevents adhesion), use single-cut or curved-tooth aluminium-specific files for soft metals, brush the file frequently during the job. Fix: file card pulled in the direction of the teeth, wood block rubbed across the faces, or the copper edge of a coin (forum-validated trick) to clear stubborn pins.

How do I clean a file properly?

File card (a stiff wire brush) drawn across the file faces in the direction of the teeth, not perpendicular. Wrong direction bends the teeth and ruins the file — this is the #1 forum-flagged file maintenance mistake. Alternative methods: a hand-sized wood block (pine/fir for light pinning, oak for stubborn pins) rubbed across the teeth, or the edge of a soft copper coin rubbed along the tooth lines (the coin sacrifices itself and removes pinning without damaging file teeth).

Can I press on the return stroke?

No. File teeth are oriented to cut on the forward (push) stroke only. Applying pressure on the return stroke drags the teeth backward against their cutting direction — dulls them rapidly. Lift the file off the work on the return stroke, or maintain only token contact. This single technique error is the most common reason factory-new files lose their cutting action within days rather than months.

What's the difference between a mill file and a flat file?

Both are rectangular cross-section but designed differently. A flat (hand) file has double cut teeth on both faces — workshop default for general metalwork. A mill file is single cut, tapered toward the tip, with one or both edges round — designed for saw tooth sharpening, lathe finishing work, and draw filing where surface finish matters. Mill files leave a finer scratch pattern than flat files of equivalent cut grade.

What size chainsaw file do I need for my saw?

Matched to chain pitch, not bar length. 1/4" pitch chains use 1/8" file; 0.325" pitch use 3/16"; 3/8" Low Profile (LP) use 5/32"; 3/8" standard use 7/32"; 0.404" use 7/32". Check the chain pitch stamped on the chain itself or in the saw manual — don't guess. Wrong file size produces wrong cutter angle, crooked cuts, and rapid dulling. AIMS stocks P&N chainsaw files in 1/8, 5/32, 3/16, 7/32, 1/4 sizes.

Files vs rasps — which for what?

Hand files have closely-spaced cut teeth (rows of cut teeth across the face) for working steel, cast iron and most metals. Rasps have individual triangular teeth raised from the body surface for working wood, leather, plastic and soft fibrous materials. Metal files clog instantly on wood and don't shape it efficiently. Wood rasps wear out fast on metal. Match the tool to the material — file on metal, rasp on non-metal.

What needle file profiles are available?

Sutton M305 T001 needle files at AIMS come in 12 profiles: Barret, Crochet, Crossing, Half Round, Knife Edge, Pippin, plus standard hand, round, half-round, square, three-square and warding profiles. Each profile suits specific detail work — Barret for flat work in tight spots, Crochet for cleaning slots, Pippin for round-bottomed work, Knife Edge for sharp angles. Eze-Lap and Pferd diamond needle files extend the range to hardened materials.

Are P&N files Australian made?

Yes — P&N is the Australian-manufacturer story in the AU file market. Same patriot positioning as Macnaught grease guns or Linishall wire wheels. P&N's range covers flat, round, half-round, three-square, square, mill, chainsaw and cabinet rasp profiles in bastard, second cut and smooth grades, sizes 100-350mm. Strong industrial supply depth at AIMS — top SKUs hold 1,000+ units in stock. "Australian Made Quality" tagged across the product line.

Why are old Nicholson files better than new ones?

Forum consensus across Practical Machinist, Hobby-Machinist and machinist communities: Nicholson files manufactured during their US-production era (pre-2000s typically) were industry-standard quality. After production shifted to Mexico and Brazil, forum-reported quality issues include softer teeth, less consistent cutting, and shorter tool life vs older US-made stock. Older Nicholson files (USA-stamped) sell at premium on second-hand markets. Modern alternatives recommended by the same forums: Pferd (German), Grobet (Swiss), Bahco (European) for premium tier; P&N for AU-industry-standard quality.

What's the best file brand?

Depends on tier. For Australian-made workshop standard volume — P&N. For German-engineered premium ("the best" per Practical Machinist forum) — Pferd. For Swiss precision needle and escapement files — Grobet (not stocked at AIMS — source on request). For specialty needle files in AU-made — Sutton Tools M305 series. For diamond files on hardened materials — Eze-Lap or Pferd diamond. Avoid unbranded cheap files — soft teeth dull within days. AIMS stocks P&N + Pferd + Sutton + Eze-Lap as the four core brand tiers.

Can I sharpen a file?

Practically, no — files are disposable consumables in modern workshops. Historical techniques exist (acid etching to deepen worn teeth, recutting teeth on specialty equipment) but the cost in time and equipment is not worth it for retail-priced files. The exception is high-value specialty files where re-cutting through a file re-cutting service may be cost-effective. For most workshops, when a file pins beyond cleaning or wears out, replace it. P&N and Pferd entry-tier files run $30-$100 — the math favours replacement over sharpening for everything except unusual specialty pieces.