This rule provides instruction on the selection of presses in stamping operations based on part type and speed.
Stamping presses are composed of a frame, a bed, a ram or slide, a drive for the slide/ram, and a power train which includes a transmission. Power may be supplied either hydraulically or mechanically.
Presses may have one or more action types. An action is defined as a stroke which produces a result on the part being worked. Each level of stroke will typically require an additional ram used. Most hydraulic presses in use are double-action presses which use one ram to position and seat the part while a second ram performs work on the part. Mechanical presses use a flywheel which runs continuously. A clutching mechanism is used to pull energy off the flywheel when a stroke is required.
Hydraulic presses may be selected when the maximum force of the stroke is required at the start of the stroke (such as deep drawing applications). Hydraulic presses are much slower than mechanical presses with an order of magnitude difference in speed being common. Hydraulic presses tend to be much less expensive when compared to mechanical presses.
While designing products which will utilize stamped components…
(a) If the part volume is low (less than 100,000) then consider using a hydraulic press.
(b) If the part volume is higher, consider using a mechanical press as tooling costs will be negligible.
(c) If the part requires finely adjusted or constant stroke pressure, use a hydraulic press.
By following this rule, product designers will produce lower cost parts when stamping is used.