This specification covers two platinum-iridium alloys in the form of rod, wire, strip, and sheet material for electrical contacts. Raw materials shall be of such quality and purity that the finished product (produced by cold working, annealing, turning, grinding, or pickling as required) will have the properties and characteristics prescribed in this specification. The alloys shall meet the requirements of chemical composition specified for platinum, iridium, total impurities, total platinum group (palladium, rhodium, osmium, ruthenium, and gold), total other impurities (including lead, antimony, bismuth, tin, arsenic, cadmium, zinc, and iron) and other elements. Ultimate tensile strength, elongation, microhardness (Knoop or Vickers), hardness (Rockwell or Rockwell Superficial), or a combination of these mechanical properties may be specified as criterion for temper designation. Annealed and work hardened wire and strip shall conform to the mechanical requirements prescribed for ultimate tensile strength, elongation, and microhardness. Knoop hardness test, tension test, and chemical analysis using spectrochemical or wet analysis method shall be performed.

1.1 This specification covers an 85 % platinum—15 % iridium alloy, and a 90 % platinum—10 % iridium alloy, in the form of rod, wire, strip, and sheet material for electrical contacts.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3 The original specification, B 684 - 81, covered the 85 % platinum 15 % iridium alloy. The 1997 revision of this specification added the 90 % platinum 10 % iridium alloy.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to become familiar with all hazards including those identified in the appropriate Material Safety Data Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.