ASTM F 288 : 1996

This specification covers three types of drawn pure and thoriated tungsten wire suitable for fabrication into parts for electron tubes, lamps, and other electron devices, and one type of rod for metal-to-glass sealing (grid wire is excepted): Type 1A, Type 1B, Type 2A, and Type 2B.

1.1 This specification covers three types of drawn wire suitable for fabrication into parts for electron tubes, lamps, and other devices; and one type of rod for metal-to-glass sealing (grid wire is excepted):

1.1.1 Type 1—ACommercially pure nonsag wire (Note 2 and Note 3).

1.1.2 Type 1—BCommercially pure rod suitable for metal-to-glass sealing.

1.1.3 Type 2—AThoriated filament wire containing 1 % thoria.

1.1.4 Type 2BThoriated filament wire containing 2 % thoria.

1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 Types 1A and 1B are designated as UNS R07005. Type 2A is designated as UNS R07911. Type 2B is designated as UNS R07912.

1.4 The following precautionary caveat pertains only to the Chemical Analysis, Section 12 of this specification: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 and health practices and determine the applicability of regulatory limitations prior to use.

Note 1—A dimensional measurement method for testing nonsag tungsten wire above 0.030 in. (0.76 mm) in diameter is provided in Test Method F 269.

Note 2—Acceptance of nonsag wire characteristics for particular applications of size shall be by agreement between producer and consumer based on either a flashed microstructure as shown by photomicrographs, or on dimensional measurement limits determined in accordance with Test Method F 269.