The cold forming process is similar to the cold heading process, however, the process uses vertical presses instead of horizontal cold heading machines. The cold forming process is also volume specific and the process uses dies and punches to convert a specific "slug" or blank of a given volume into a finished intricately shaped part of the exact same volume. The cold forming process generally compliments the cold heading process by adding more intricate shapes to the cold headed blank.
Equipment & Tooling
The basic type of equipment used in cold forming is a vertical press either manually fed or fully automatic. Vertical presses can be powered mechanically or hydraulically. Stalcop uses vertical presses from both technologies in a range from 5 tons to 1000 tons with strokes from 4 inches to 36 inches and speeds from 7 pieces per minute to 50 pieces per minute.
The two major components of cold forming tooling are punches and dies. Punches transfer the required force from the machine to the material and provide close dimensional control on the internal part features. Dies confine and direct the material into the desired geometry and provide close dimensional control on the external part features.
Single Step Cold Forming Process
Types of Cold Forming Shapes
This technique reduces the outside diameter by thinning the side walls. It also is used to size the inside diameter and outside diameter of a part. The material that is moved goes into the overall length. Ironing is usually a secondary operation. 10-20% are reductions are possible in one pass.
Flaring is used to increase the outside diameter and inside diameter of the open end of a hollow cylindrical part. Slight wall thinning will be experienced. Two times the starting diameter can be achieved. An included angle of 60° or less is preferred.
These techniques are not exclusive of each other and can be performed simultaneously with creative design to minimize production costs.
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