Roll-welding precious metals for telephone contacts

THE roll-welding process has been used for years at the Western Electric Company for fabricating tapes for precious metal contacts. A thin strand of palladium a few thousandths of an inch thick and about 0.010 inch wide is roll-welded to a nickel tape of larger section to facilitate handling of the short lengths required in the contact-welding machines. Many millions of contacts are required in the telephone equipment manufactured each year and many contact welders are used.