"ALEMITE" TAPER THREAD GREASE FITTING Used on most cars and trucks and many industrial machines. It is recommended that SAE-LT taper threads be assembled into 1/4"-28 UNF, Class 3B, straight-threaded holes having a modified maximum minor diameter of 0.2151 in. to insure 75% minimum thread height.Highlights:Type: straight-threaded.Overall Length:1-5/8"Shank Length: 1"Hex Size: 5/16"Maximum pressure: 8,000 ps.i Exceeds 48-hour salt-spray test. Dirt-excluding ball check.