Flat Head Socket Cap ScrewsFlat head screws go countersunk into the receiving material. This allows a smooth finished surface once the bolt or screw is in place.
U.N.R.F. Fine Thread/Class 3A Threads
Tensile Strength:145,000 psi. min. (thru 1/2" diameter)
135,000 psi. min. (over 1/2" diameter)
Manufactured to ASME B18.3 specifications / Heat Treated Alloy Steel