Metal spinning comes by different name from metal turning, spin forming or spinning; this is a process of metalworking to which the tube or disc of metal is rotated at high speeds in order to form it into axially symmetrical part. Spinning can be done as well by either a CNC lathe or by hand. Metal spinning normally consists of the removal of material like in traditional metal or wood turning. However, forming or molding of sheet material is over an existing shape.
Actually, metal spinning is ranging from the artisan’s specialty to the most sophisticated way of forming round metal parts primarily for commercial applications. As a matter of fact, artisans are utilizing this process as a way to generate architectural detail, decorative household goods as well as urns and specialty lighting too.
Commercial applications for metal spinning process is quite a lot and this includes rocket nose cones, cookware, gas cylinders, brass instrument bells, public waste receptacles and so forth. Fact is, any ductile metal can be formed from stainless steel, aluminum to high strength and high temperature alloy. Both the depth and diameter of formed parts are only limited by the size of available equipment.
The process of spinning is quite simple; in drive section of lathe, a formed block will be mounted and then, pre-sized metal disk is clamped against the block using pressure pad, which is attached to tailstock. The block and workpiece are rotated together at fast speeds. Local force is applied in the workpiece in order to make flow to the block. Usually, the force is being applied through different levered tools. Simple workpieces are removed from the block but more complex shapes might require several blocks.
When it comes to complicated shapes, it is typically spun on ice forms that then melts after spinning. Because the final diameter of workpiece is less than the starting diameter, the workpiece ought to be thickened, buckled circumferentially and elongated radially.
For the more involved procedures, it’s referred to necking or reducing, it allows the spun workpiece to incorporate reentrant geometries. If for example that the surface form and the finish is not that hard, the workpiece is spun on air and no mandrel ought to be used. But the form or finish will need eccentrically mounted mandrel if it is more complicated.
There are also the metal spinning tools allowed on bearings throughout forming process. What these tools do is reduce heating and friction of the tool, improve surface finish while prolonging its life. The rotating tools can be coated too with a thin film of ceramic as a way to prolong the tool’s life.