What is multi- pass Metal Spinning?

Metal spinning is a rotary forming process for the production of hollow, rotationally symmetrical parts in sheet metal. The starting blank is usually a flat disc but may also be a tube or a pressed pre-form. In a series of sweeps and employing a forming roller, the metal is progressively shaped onto a mandrel conforming to the internal form of the finished part whilst the work-piece is rotated.

What metals can be spun?

All ductile metals can be spun and tougher materials can often be spun by the application of heat.

Why spinning rather than press?

In general, spinning offers flexibility with low tooling costs and is widely used for low- to medium-volume production. Depending on the application, spinning can offer major benefits which makes it first choice, even for high-volume production. Production machines can be configured with a range of attachments to produce a finished part in one hit eliminating secondary operations. Each case needs to be examined on its own merits.

Economics of Metal Spinning

The cost-effectiveness of metal spinning and shear forming is characterised on the one hand by the possibility of combining the two techniques and on the other by the range of secondary forming or machining operations which can be carried out in the same set-up.

Compared to methods such as pressing and deep drawing, spinning and shear forming involve lower forces and require loss power. This in turn means that the equipment can be cost-effectively engineered in terms of rigidity and size as well as a number of individual assemblies.

What is shear forming?

In contrast to multi-pass spinning, so called “shear forming” produces the final component in a single roller pass.

Shear forming is a variant on spinning applied to the manufacture of conical or other shapes. Unlike multi-pass spinning, the wall thickness of the work-piece is deliberately reduced in a single pass of the work roller, the reduction being a direct function of the change in angle.

What are the practical applications for these techniques?

There are a thousand and one applications for spinning ranging from the everyday, such as pots and pans, to the exotic, such as parts for satellites. Spinnings are widely found in the lighting, heating and ventilating, bulk storage and transport, food, medical, giftware and automotive industries.

The Historical Development of Spinning.

What today is classified as spinning encompasses some of the oldest known methods of re-shaping materials and is derived from the ancient Egyptian art of a potting wheel?. The rapidly-rotating manually-powered potter’s wheel, known to be in use some 3000 years before the birth of Christ, provided the basis for the art of spinning.

The first pointers to the existence of spun parts such as silver tableware or the rims on a circular iron shields were recorded in 25BC.

Today Tanfield are able to offer CNC / PNC from 25mm to 3000mm diameter. (please refer to our capacity list.)