Electrical contact arm material and method of making

Claim 2

A composite strip material for use in making electrical contact arms and the like comprising a strip of composite electrically conductive spring material having a layer of copper sandwiched between and metallurgically bonded to two outer layers of stainless steel, said stainless steel layers of said spring material embodying at lease partially hardened stainless steel alloys selected from the group of alloys comprising an alloy having an approximate composition by weight of 0.09 percent (max.) carbon, 1.00 percent (max.) manganese, 1.00 percent (max.) silicon, 14.00 to 16.00 percent chromium, 6.50 to 7.75 percent nickel, 2.00 to 3.00 percent molybdenum, 0.75 to 1.50 percent aluminum and the balance iron and an alloy having an approximate composition by weight of 0.15 percent (max.) carbon, 2.00 percent (max.) manganese, 1.00 percent (max.) silicon, 16.00 to 18.00 percent chromium, 6.00 to 8.00 percent nickel, 0.045 percent (max.) phosphorous, 0.030 percent (max.) sulfur, and the balance iron, said stainless steel layers being of substantially equal thickness comprising from about 25 to 38 percent of the total thickness of said composite spring material, said spring material having a stripe of gold secured to said spring material extending along the length of said strip of spring material and at least one of said stainless steel layers having a stripe of solder material continuously adhered thereto extending along the length of said strip of spring material.