swage

Swage is a term used in metalworking to describe tools, blocks, and processes that form metal by deformation rather than cutting. The common idea across uses is shaping metal through hammering, pressing, or upsetting to achieve a desired contour or joint.

As a tool, a swage is a shaped instrument used with a hammer or press to form metal against a stake, anvil, or other forming surface. Swage tools come in various profiles to create curves, hollows, beads, and other features on sheet metal or formed pieces. A swage block—a large, hardened block with multiple depressions, grooves, and holes—serves as a stationary forming station, enabling smiths and fabricators to work metal into accurate shapes by tapping, bending, or staking against the configured surfaces.

As a process, swaging refers to deforming metal to reduce its diameter or to join components by upsetting the metal around a mandrel or die. In piping and tubing, swaging commonly means expanding or constricting tube ends so they can fit together or over fittings, often without welding. Methods include mechanical swaging, which uses dies on a press or rotary tool, and hydro-swaging, which uses high-pressure fluid to achieve the form.

Applications span several trades. In blacksmithing and metal fabrication, swage blocks and swaging tools enable the creation of complex curves, joints, and decorative features. In plumbing and HVAC, swaged fittings and tube ends facilitate tight, seamless connections. In jewelry and small-work metal, swage tools support forming thin metal into precise shapes and decorative elements.