Steel alloy, cadmium plate, lubricated with cethyl alcohol, ultimate tensile strength 200000 psi, thds 1/2-20 unjf-3a, fastener lgmin 2.100 in. Max 2.125 in., gripe lg min 1.615 in. Max 1.630 in., thd lg min 0.470 in. Max 0.510 in., 100 degree countersunk head, temperature rating 450 degree f