The hammer is among the oldest and most indispensable tools in the jeweller's workshop, employed across virtually every stage of metal fabrication — from rough forming and raising to delicate planishing, riveting, and surface texturing. Unlike the blunt-force instruments of general metalwork, jeweller's hammers are precision tools, each type engineered with a specific head geometry, face profile, and weight distribution to accomplish a defined task without introducing unwanted distortion or stress into the workpiece.

Types and Their Functions

The jeweller's bench typically holds several hammer types, selected according to the operation at hand:

• Ball-peen hammer: Features one flat face and one domed (ball) face. The flat face drives punches, stamps, and rivets; the ball face stretches and moves metal, and is commonly used to create texture or to begin doming sheet stock.
• Planishing hammer: Has two slightly convex, highly polished faces. Used to smooth and refine a surface after raising or forming, planishing removes hammer marks and consolidates the metal's surface, producing a refined, even finish.
• Chasing hammer: Characterised by a broad, slightly domed face and a weighted, bulbous handle that allows it to be rolled between the fingers during repetitive chasing strokes. The weighted head reduces fatigue and provides a consistent, controlled blow when driving chasing and repoussé tools.
• Raising hammer: A heavier tool with a cross-peen or narrow rounded face, used to move large volumes of metal during the raising of hollow forms such as bowls, vessels, and bezels from flat sheet.
• Riveting hammer: A lightweight hammer with a very small, precisely ground face, designed for setting rivets and performing delicate cold-joining operations where control of force is paramount.
• Nylon or rawhide mallet: Strictly speaking a mallet rather than a hammer, but functionally grouped with hammers on the bench. The non-marring face moves and adjusts metal — particularly on mandrels — without hardening or marking the surface.

Materials and Face Finish

Hammer heads are most commonly forged from hardened tool steel, which is then ground and polished to the required face profile. The condition of the face is critical: any nick, scratch, or pit on a planishing or forming face will be transferred directly to the metal with each blow. Jewellers maintain their hammer faces with fine abrasive papers and polishing compounds, treating the tool with the same care afforded to any precision instrument. Brass-faced hammers are used where a softer blow is required, and nylon-faced hammers serve wherever the workpiece must not be marked at all.

Technique and Work-Hardening

Effective hammer technique demands control of three variables simultaneously: force, angle of impact, and rhythm. Blows delivered at an inconsistent angle cause the metal to move unevenly; excessive force in a single area creates thinning and potential fracture; and irregular rhythm produces an uneven surface that requires additional planishing to correct. As metal is worked, the crystalline structure deforms and the material becomes progressively harder and more brittle — a phenomenon known as work-hardening. The jeweller must anneal (heat and slowly cool) the workpiece at intervals to restore ductility before continuing to hammer, particularly during raising or extensive forming operations.

Use with Supporting Tools

Hammers are rarely used in isolation. They work in concert with a range of supporting tools that provide the necessary resistance and form against which the metal is shaped:

• Stakes and anvils provide rigid, shaped surfaces for forming and planishing.
• Mandrels — tapered steel rods of circular, oval, or other cross-section — support rings, bangles, and tubes during forming and sizing.
• Sandbags and pitch bowls provide a yielding, supportive surface for repoussé and chasing work, allowing the metal to move freely under the chasing hammer without cracking.

In the Trade

Despite the widespread adoption of hydraulic presses, rolling mills, and die-forming equipment in commercial production, hand-hammering remains the mark of the bespoke jeweller and the silversmith. Hammer-raised forms carry a characteristic surface quality — a subtle, faceted planish or a deliberate texture — that is impossible to replicate mechanically and is actively prized in studio jewellery and high-end handmade pieces. Auction catalogues and exhibition notes frequently cite hand-raising and hand-planishing as indicators of craft quality and maker involvement, distinguishing individually wrought work from industrially formed production.