Double-End Threaded Stud Material Steel Material Grade/Class Class 8 Finish Black Oxide Overall Length 42 1/2 mm System of Measurement Metric Thread Length A 7 1/2 mm Thread Length B 18 mm Thread Size A M6-1 Thread Size B M6-1 Dimensional Standards DIN 939 Rockwell Hardness C22 to C32 Package Quantity 100