1.1This specification covers two iron-nickel alloys and one iron-nickel-cobalt alloy, for low thermal expansion applications. The two iron-nickel alloys, both containing nominally 36 % nickel and 64 % iron, with the conventional alloy designated by UNS No. K93603, and the free-machining alloy designated as UNS No. K93050. The iron-nickel-cobalt alloy, containing nominally 32 % nickel, 5 % cobalt and 63 % iron, is designated by UNS No. K93500. This specification defines the following product forms for UNS No. K93603 and UNS No. K93500: wire, rod, bar, strip, sheet plate, and tubing. The free-machining alloy, UNS No. K93050, is defined for bar products only. Unless otherwise indicated, all articles apply to all three alloys.

1.2The 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.

1.3This pertains only to the test method section, Section 13. 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 establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.