Stackpole Limited

Extending the Capabilities of Powdered Metal Parts

Stackpole has created high load-bearing powdered metal parts, with a more complex geometry than can be economically machined from conventional forgings, at a cost savings of 30-40%. This innovation enlarges the envelope for complex mechanical component design at costs comparable to those of simple geometry parts.

An example of such a part is the Gemini sprocket now used on GM 4T65 and 4T40 front wheel drive transmissions. The phased-tooth design is pressed in a unique split die, and the load-bearing surfaces are hardened with Stackpole’s SelectDens™ process. The phased-tooth design reduces transmission noise, while eliminating the use of an extra sleeve bearing. Without the new Stackpole powdered metallurgy processes, such a design would be feasible only at a high premium cost.

This innovation included several process stages, beginning with customized powder formulation. The Stackpole SelectDens™ process promises not only to make powdered metal parts cost-competitive with existing heat treated, low alloy steel components, but to improve cost and performance of the subassemblies in which they are used through more imaginative overall design.

SelectDens™ and other process innovations have resulted from an ongoing fifteen year program in powdered metal R&D, a competence in which Stackpole intends to remain a leader. They are enthusiastically developing further innovations in powdered metallurgy, and their award-winning technology should enable their customers to create award-winning designs for some time to come.