Investigation of a combined micro-forming and punching process for the realization of tight geometrical tolerances of conically formed hole patterns

The outer shaving foils in electrical shavers are made from nickel through a galvanic deposition process, which are the subject of restrictions to eliminate allergic hypersensitivity to nickel. The substitution of this material through a stainless steel would require new manufacturing technologies to meet such parts' specifications. Narrow patterns of micro holes with raised edges smaller than Ø0.53 mm were punched into a 1.4310 sheet having a tensile strength of 1200 MPa. This paper summarizes the process development and presents the results gained through a feasibility study. Experimental investigations were carried out with special concern to the influence of punch and die geometry on process forces and finished part accuracy.