DIN 933 Hex Head Cap Screws
DIN 933 Hex Head Cap Screws are fully threaded, have external coarse machine screw threads and, like other hex head screws, are used with both tapped holes and nuts. Their dimensions are similar to ISO 4017 and are available in Class 8.8, 10.9 and 12.9 steel and Class 70 (A2-70, A4-70) stainless steel; less common stainless steel sizes may be Class 50. Zinc plating protects against corrosion while plain finish is unplated and can rust. A2 stainless steel is considered the same as 18-8 and A4 is essentially 316. Class 8.8 and 10.9 thread tolerance for plain finish is 6g and 6h for plated; stainless steel is 6g; right-hand threads are standard. Also known as hex head bolts and tap bolts, all lengths are fully threaded. Length is measured from under the head to the tip. DIN 933 Hex Head Cap Screws are similar to ISO 4017, JIS B1180 and ANSI B18.2.3.1M. In contrast, DIN 931 is partially threaded and DIN 961 has fine threads. (Note: Thread pitch, the distance between threads, is traditionally omitted for fasteners with coarse threads but is included here for reference.)