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. The screw has a length of 7 and a thread of 1-3/8-12.
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.