Jeweller's files are hardened steel hand tools bearing cut or milled teeth, used at the bench to remove excess metal, refine contours, adjust settings, and prepare surfaces for soldering or polishing. Among the most fundamental of all bench tools, they are found in every professional workshop and are indispensable at virtually every stage of fabrication — from roughing out a casting to the final dressing of a bezel before stone-setting.

Construction and Tooth Cut

A file consists of a hardened steel blank onto which rows of teeth are cut, either by hand chisel (in traditional Swiss manufacture) or by machine. The teeth are formed in one or two directions: single-cut files have parallel rows running at an angle to the axis and produce a smoother finish; double-cut files have two intersecting sets of rows and remove metal more aggressively. The hardened blank is typically left unhardened at the tang — the pointed shank that fits into a wooden or composite handle — so that it remains tough rather than brittle at that junction.

Coarseness Grades

Files are graded by the density of their teeth, expressed as a cut number. The standard range used in jewellery work runs from cut 0 (coarse, sometimes called bastard cut) through to cut 6 (very fine, sometimes called needle smooth). In practice, most jewellers maintain a working set spanning cuts 2 through 4, reserving coarser grades for rapid stock removal and finer grades for work that is close to the polishing stage. The Swiss grading system — widely adopted internationally — is the benchmark against which other manufacturers' grades are measured.

Profiles

Files are produced in a range of cross-sectional profiles, each suited to particular tasks:

• Flat — the most versatile profile; used for flat surfaces, inside angles, and general shaping.
• Half-round — flat on one face, curved on the other; invaluable for working inside curved settings and ring shanks.
• Round — used to enlarge holes, open up jump rings, and file concave curves.
• Square — suited to right-angle recesses and box settings.
• Triangular (three-square) — useful for internal corners, prong grooves, and decorative V-cuts.
• Knife — a thin, wedge-shaped profile for reaching into tight angles and undercutting.
• Barrette — teeth on one face only, allowing work in a confined space without damaging an adjacent surface.

Needle Files

Needle files — also called escapement files — are a subset of jeweller's files distinguished by their small diameter and uniform, slender profile. Typically 140–160 mm in overall length with a working surface of approximately 60–70 mm, they are used for detail work: cleaning up filigree, refining prong tips, opening settings, and working in areas inaccessible to full-sized files. They are sold individually or in sets of assorted profiles and are available in the same range of cut grades as standard files.

Swiss-Made Files

Switzerland has been the pre-eminent centre of precision file manufacture since the eighteenth century, and Swiss-made files — produced principally in the Jura region — remain the preferred choice for professional jewellery work. The consistent tooth geometry, reliable hardness, and longevity of Swiss files justify their higher cost relative to mass-produced alternatives. Brands such as Vallorbe (Grobet) are well established in the trade and stocked by major jewellery supply houses worldwide.

Care and Use

Files cut on the forward stroke only; applying pressure on the return stroke dulls the teeth prematurely. Keeping a file clean is essential: metal filings lodge between the teeth and reduce cutting efficiency, a condition known as pinning. A file card — a brush with short wire bristles — is used to clear the teeth regularly during use. Files should be stored so that they do not contact one another, as the hardened teeth are brittle and chip easily. A worn file cannot be resharpened economically and is replaced rather than reconditioned.