DIN 912 Socket Head Cap Screws
DIN 912 Socket Head Cap Screws have a small diameter cylindrical head, a hex socket recess and external machine screw threads; the side of the head may be plain or knurled. Internal wrenching allows for close screw spacing and the head can be recessed in a counterbored hole. Unlike inch series screws, which are available in a single strength grade, steel metric socket head cap screws are available in three grades: Class 8.8, 10.9 and 12.9. There may also be three grades in stainless steel: Class 50, 70 and 80; most are Class 70 (A2-70, A4-70) and some are Class 80 (A4-80), but unusual sizes could be Class 50. Consequently, check the head marking and replace metric socket head cap screws with the same Class. Available in zinc plated and plain finish (unplated) steel, stainless steel and nylon; A2 stainless steel compares to 18-8 and A4 to 316. Thread tolerance is 5g6g for Class 12.9 and 6g for Class 8.8 and 10.9 and stainless steel; right-hand threads are standard. Measure length from under the head to the tip. DIN 912 Socket Head Cap Screws are similar to ISO 4762 and ANSI B18.3.1M. DIN 7980 High Collar Split Lock Washers and DIN 433 Small Pattern Flat Washers are small OD (outside diameter) washers that are used with socket head cap screws.