How to Use a Letter & Number Punch Set for Metal Stamping

By Jewellery Tools UK — Hand Tools for Jewellers & Silversmiths | Published: 2026-11-03

Category: Guías prácticas

Learn a steady, repeatable process for stamping initials and dates into metal with a 3mm letter and number punch set, including how to avoid double strikes.

Quick answer

Clamp the metal firmly on a steel block, align each punch vertically, and strike once with a firm hammer blow. A single confident strike is the most reliable way to stamp metal without double strikes.

Why a single strike matters more than force

A double strike happens when the punch shifts between two lighter blows, so the character prints twice with a slight offset. The fix is not to hit harder but to hit once, squarely, with enough force to sink the character to a consistent depth. Practise on scrap metal of the same thickness and temper before you touch a finished piece.

Tempered steel punches are designed to mark metal directly, but they are not indestructible. Strike the punch head, never the character end, and keep the punch vertical so the force travels straight down the shaft.

When 3mm characters are the right size

A 3mm character height suits ring shanks, charms and small pendants where initials and dates must stay legible without overwhelming the piece. On very narrow bands, check that the full character width fits before you commit; if it does not, choose a smaller set or reposition the mark.

If you are marking silver, your own maker's mark or initials sit alongside official hallmarks, so plan the layout to leave room for both. The punch set does not replace hallmarking requirements; it only adds your personal mark.

Step-by-step: stamping metal with a letter and number punch set

Prepare the surface and layout: Clean the metal, mark a centre line with a fine scribe or marker, and space your characters with a ruler. Check the layout on paper first, remembering that each 3mm character needs clearance on both sides. If the spacing looks tight on paper, it will look tighter in metal; adjust before striking.
Secure the workpiece on a steel block: Place the metal on a solid steel bench block and clamp or hold it firmly so it cannot slide. A folded cloth or soft backing will absorb the blow and blur the impression. Test that the metal does not move when you press down on it.
Hold the punch vertical and aligned: Set the punch on the mark with the character facing the correct direction, then check from the side that the shaft is upright. Rest the punch flat on the metal rather than tilting it toward you. A punch that leans will produce a shallow, uneven character even with a hard blow.
Strike once with a firm hammer blow: Use a heavy hammer and deliver one decisive blow to the punch head. Do not tap repeatedly; if the impression is too shallow, reposition and strike once more rather than adding several light hits. One firm strike beats three light ones for avoiding double strikes.
Check depth and alignment before moving on: Lift the punch and inspect the character under good light. If it is uneven, correct your angle on the next character rather than trying to deepen the same mark, which risks a double strike. Keep a scrap test piece beside you to compare depth as you work.
Finish and clean the stamped area: Remove any burr with a fine file or abrasive stick, then polish lightly around the marks. Avoid over-polishing, which can soften the character edges you have just cut. Clean the punch tips with a soft cloth after use to prevent rust and transfer marks.

Product facts

Letter & Number Punch Set — 37 Tempered Steel Metal Stamps, 3mm, A-Z, 0-9 & Ampersand: A 37-piece set covering A-Z, 0-9 and an ampersand, each stamping a 3mm character. The full alphabet and numerals let you stamp initials, dates and short messages without buying separate sets, and 3mm is a practical size for ring shanks and small pendants.
Letter & Number Punch Set — 37 Tempered Steel Metal Stamps, 3mm, A-Z, 0-9 & Ampersand