MRC:
The specification,standard,or manufacturers reference,and the classification designation,such as class,condition,temper,and the like,that identifies the screw material.CYAW
Screw Material Specification:
Qq-s-633 federal specification 1st material response or qq-s-630 federal specification 2nd material response or qq-s-630 federal specification 3rd material response or qq-s-631 federal specification 4th material response or qq-s-631 federal specification 5th material response or qq-s-634 federal specification 6th material response or qq-s-634 federal specification 7th material response