Socket Head Cap Screw Fine Thread Black Steel 1/4-28 * 1-5/8″ Grade 8 [Cup Point] [Allen Drive] Supply

With a tensile strength of 170,000 psi, these Alloy steel screws are stronger than Grade 8 steel screws. Length is measured from under the head.

Alloy steel screws are mildly corrosion resistant in dry environments. Fine and extra-fine threads are closely spaced to prevent loosening from vibration: the finer the thread, the better the resistance. They are not compatible with coarse threads.