9.1 Proprietary methods for manufacture of these materials vary significantly among suppliers, and these methods influence such properties as arc erosion, contact resistance, and tendency to weld in service. Since the performance of contacts in a device depends on numerous factors outside the contact itself (opening speed, closing speed, contact pressure, contact bounce, environmental variations, assembly technique and variations, etc.) this specification cannot ensure performance control in the application. As part of the qualification on initial samples it is recommended that the user functionally electrically test the materials for all devices applicable to the material's use. This specification will provide a means for the contact manufacturer and contact user to reach agreement on the details of material to be supplied for a specific use and reasonable assurance that future lots will be similar in properties and microstructure to the initial test or sample contacts supplied.

This specification covers electrical contact components made from silver-tungsten by powder-metallurgical procedures. The material shall conform to composition limits specified. The material shall be finished by braze alloy backing, tumbling to polish surfaces, special surface finish, silver-rich surface layer, cleaning, etc. Chemical analysis and physical test shall be made to conform to the specified requirements.