The lathe is one of the most versatile machine tools. When the lathe is operating the work piece is rotating. Metal spinning was originated by the Egyptians. In 1840 metal spinning was finally introduce in the United States. The shaping of a material takes place when the metal disc is forced over a piece of wood called a chuck.
Metal spinning is quite similar to a potter forming his clay except a metal spinner uses a flat round disc of sheet metal rotating on a spinning lathe. The metal spinner applies pressure
to the rotating blank to shape the metal over a form we call a chuck or mandrel. This pressure can be applied by a single tool, compound levers or hydraulically. The path of the tool can be controlled by hand, by a template or by full CNC.
Spun metal parts are all around you. Perhaps your cooking pots at home? The wheels on your car? The jet engine cowling on the plane you took on your last business trip. We would not have been able to send men to the moon if it were not for metal spinning.
Paul Revere was a metal spinner... his hollow ware is in museums. Remember the Jefferson Cup? Spinning is a great means for manufacturing low cost rapid prototypes in metal, because it requires a minimum of time and money to produce parts. An average part can be spun in five to ten (5-10) minutes once one is familiar with the process.
Smooth parabolic curves (bell form) are ideal for spinning as the metal is comfortable deforming along a parabolic curve. The venturi form of velocity stacks for racing car carburetors is a common application of the spinning technology. A solid cylinder such as a Coca-cola can be spun, but a minimum of draft angle is required to pull the part back off the form (see mandrel section for more). Elliptical and off-center forms can be created, but they require great care and patience. pinning is a great means for manufacturing low cost rapid prototypes in metal, because it requires a minimum of time and money to produce parts. An average part can be spun in five to ten (5-10) minutes once one is familiar with the process.
Smooth parabolic curves (bell form) are ideal for spinning as the metal is comfortable deforming along a parabolic curve. The venturi form of velocity stacks for racing car carburetors is a common application of the spinning technology. A solid cylinder such as a Coca-cola can be spun, but a minimum of draft angle is required to pull the part back off the form (see mandrel section for more). Elliptical and off-center forms can be created, but they require great care and patience.
Spinning is a great means for manufacturing low cost rapid prototypes in metal, because it requires a minimum of time and money to produce parts. An average part can be spun in five to ten (5-10) minutes once one is familiar with the process.
Smooth parabolic curves (bell form) are ideal for spinning as the metal is comfortable deforming along a parabolic curve. The venturi form of velocity stacks for racing car carburetors is a common application of the spinning technology. A solid cylinder such as a Coca-cola can be spun, but a minimum of draft angle is required to pull the part back off the form (see mandrel section for more). Elliptical and off-center forms can be created, but they require great care and patience. 
There is also the opportunity to create concentric strengthening ribs which add dramatically to the stiffness and strength of the part. These can be formed directly (over the mandrel) or spun in the air (tricky) as the part is closed down onto the mandrel. An edge may also be folded over itself or with wire inside to create a finished, smooth edge to the part.
Almost every metal that is available in sheet form may be spun (tubing can be pinched or swaged but is usually made from harder alloys). However, a few metals are ideally suited to the art of spinning. Aluminum is fantastically elastic and easy to form so long as it has been annealed. The softer (i.e. purer, non-alloyed) the aluminum the better. Hence, 3003 is better than 5052 , and 1100-0 is the best to use especially since 3003 doesn’t anodize very well. However, 5052 is the strongest work hardening aluminum, but harder to form. Try to buy the aluminum sheet annealed (1100-0, 3003-0, etc.; not 1100-H32, 6061-T6, etc.). H denotes strain hardenable aluminums and T denotes thermally treated aluminums. Sheet metal can be spun in thicknesses of 0.040" to 0.100" with hand tools.Stainless steel is even more elastic (stretching before tearing) than aluminum (50%-68% elongation!) but requires significantly more force to form.
The Austenitic range (200-300 series) of stainless steels form best, 201 and 301 having the greatest elongation. Similarly, the lower the Carbon content in mild steel the easier it is to form. Copper has excellent elongation (very formable) and doubles its tensile strength when work hardened, but if it hardens before the part is finished then the part must be annealed to prevent shearing and cracking. Brass is a copper-zinc alloy and has similar properties to copper in its formability but brass work hardens less and requires more force. Other exotic metals may be spun: titanium, magnesium (@ 600°F), silver, gold, etc., but they require extra care and consideration.
Metal spinning is one of the oldest methods of forming sheet metal. It's also one of the fastest growing. New uses are being found for the spinning process all the time. Perhaps you can come up with the next new idea? Give us a call and let AD Metal Spinning work with you.