ASTM International

Standard Specification for Tungsten Wire for Electron Devices and Lamps
 N F288

Annotation

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):

Type 1A—Commercially pure nonsag wire (Note 2 and Note 3).

Type 1B—Commercially pure rod suitable for metalto- glass sealing.

Type 2A—Thoriated filament wire containing 1 % thoria.

Type 2B—Thoriated filament wire containing 2 % thoria.

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.

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

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 F269.

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 F269.