4X1/4 MS21318 Military Round Head Type U Drive Screw Cadmium (Pack Qty 5,000) BC-MS21318-21

PICTURES ARE REPRESENTATIVE OF ITEM, BUT ARE NOT OF THE ACTUAL ITEM. Product dimensions, finish, head markings, thread length, stamping shape or forging shape, etc., may differ from picture. Products are guaranteed to meet the specifications to which they are manufactured. Specifications allow for tolerances in dimension and shape, which can vary from lot to lot. Class 04 metric hex jam nuts are tightened against the work surface and a Style 1 or Style 2 hex nut is tightened against the jam nut to keep it from loosening. Class 50 A2 stainless hex jam nuts are used in the same manner with A2 stainless screws. Class 04 hex jam nuts shall be made of a steel that conforms to the following chemical composition-- Carbon: 0.58% maximum; Manganese: 0.25% minimum; Phosphorus: 0.060% maximum; Sulfur: o.150% maximum. Class A2 stainless steel. HV 188 - 302 (Rockwell B88 - C30).