ASTM F 288

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. Types 1A and 1B are designated as UNS R07005; Type 2A is designated as UNS R07911; and Type 2B is designated as UNS R07912. The wire and rod shall conform to the prescribed chemical requirements for thoria and tungsten and to the specified physical properties such as tensile strength, ductility, and surface defects. The weight/diameter conversion formulas are given. Wires shall be furnished in the following specified finishes: Finish 1, Finish 2, Finish 3, Finish 4, Finish 5, Finish 6, and Finish 7. The material shall be smooth, free of twists, bends, kinks, curls, and as free of dents, swaging marks, scratches, die marks, laps, seams, splits, slivers, inclusions, bumps, pits, grooves, cracks, and other physical defects Unless black finish is specified, all types of wire shall have a clean finish, free of graphite, grease, oil, and lubricants. Wire for hooks, supports, springs, anchors, and mesh shall have a bright smooth surface free of cracks holes, or craters. The requirements for straightness, and coiling and spooling are detailed as well. The following analysis and tests shall be performed: chemical analysis, tensile test, ductility test, visual inspection, dimensional measurements, and examination for surface flaws.