ASTM International Standard Test Method for Sag of Tungsten Wire ASTM F269-60(2002)

This test method covers a determination of the sag properties of tungsten wire. The specimen of tungsten wire to be tested for sag shall have a clean, bright surface and should have the required length. With the aid of external heat, the test specimen shall be bent into a hairpin-shape until it reached the required distance between the ends. The formed test specimen shall be of sufficient length so that when clamped in the fixture, the exposed lengths measured from the top of the apex will be of required distance.