Metal spinning

The metal spinning trade is one that dates back to antiquity and was a skill used in the Ancient Egyptian era.

Artisans use the process to produce architectural detail, specialty lighting, decorative household goods and urns.

Commercial applications include rocket nose cones, cookware, gas cylinders, brass instrument bells, and public waste receptacles.

Virtually any ductile metal may be formed, from aluminum or stainless steel, to high-strength, high-temperature alloys including INX, Inconel, Grade 50 / Corten, and Hastelloy.

A pre-sized metal disk is then clamped against the block by a pressure pad, which is attached to the tailstock.

[1] A more involved process, known as reducing or necking, allows a spun workpiece to include reentrant geometries.

Parts can then be shaped or necked down to a smaller diameter with little force exerted, providing a seamless shoulder.

Cutting of the metal is done by hand held cutters, often foot long hollow bars with tool steel shaped/sharpened files attached.

The mandrel does not incur excessive forces, as found in other metalworking processes, so it can be made from wood, plastic, or ice.

[1] Other methods of forming round metal parts include hydroforming, stamping, forging and casting.

As machinery for commercial applications has improved, parts are being spun with thicker materials in excess of 1in (25mm) thick steel.