Most handmade jewellery needs files at some point: they thin metal, shape, define and contour, smooth and refine surfaces, apply textures, even carve patterns. After sawing, drilling, forging, bending or cutting, edges come off the tool sharp enough to cut skin or catch in clothing — running a file over every cut edge is basic bench hygiene. And before soldering, files are how two parts are brought into the precise contact a good join demands; solder never forgives a bad seam.
Files cut in one direction only
Files are high-quality steel, forged, annealed, then incised with diagonal or parallel lines — the cutting teeth, all facing the same direction: forward. The file should always be pushed away from you across the metal. Pulling backwards has no effect at all, no matter how hard you pull — it wastes time and dulls nothing but your confidence. This one fact separates people who have been taught from people who are guessing.
Cut numbers: coarse to fine
The cut — the number — says how coarse or fine the teeth are. The jeweller's scale runs:
- #00 ('double-aught') — the most coarse
- #1 super coarse; #2 very coarse — a good beginner hand file
- #3 slightly coarse; #4 medium — a good beginner needle file
- #5 slightly fine; #6 very fine; #7 super fine
- #8 — the finest, for extremely delicate work
For deep scratches, work through a series from coarser to finer — each file removing the marks of the last, exactly like grits in sanding.
The eight shapes that matter
- Equalling — teeth on three sides, for levelling flat surfaces; the dead face (one narrow toothless side) protects metal when working up to an inner corner.
- Round (rat tail) — teeth cover the whole surface; makes holes perfectly round.
- Half-round — curved one side, flat the other, teeth both sides: the versatile one. Curved side for concave inside edges, flat side for convex shapes — never the other way around.
- Square — teeth on all sides, for 90° grooves in sheet or wire and perfect corners in pierced work.
- Three-square (triangle) — for scoring and 60°-edged windows.
- Crossing — curved, teeth both sides, made for finishing the inside edges of rings, bracelets, anything concave.
- Knife — tapering, three-sided, for tight spaces.
- Barrette — teeth on one flat face only, fine-edged dead back; gets into tight spaces without scratching adjacent metal.
Technique: brace, shoulder, patience
Filing happens at the bench pin, where the piece is braced and you can exert exactly the right force. Without that solid contact the file wanders — through a finger, or into uselessness: air-filing is the mock-name for a beginner filing nothing stably. Though the file is held in the hand, the motion is propelled by the shoulder, the arm doing the work rather than the wrist. Smooth, even strokes make smooth, even surfaces, and patience is the actual skill — the motion repeats many, many times.
For symmetrical pieces: work the coarse file a little on one side, then the opposite — 'file a little, look a lot' — turning the piece frequently to keep shape and surface uniform. Coarse file over all parts first, then step down through finer files to the goal. And the caution that ends the lesson: never point a file toward your person or your hand.
Grounded in the JDMIS Metalsmithing (MS100) course materials. Learn filing hands-on in Foundation Metalwork Skills. Related reading: The Jeweller's Saw and Achieving a Professional Jewellery Finish.