Socket Head Cap Screws DIN 912 (GB/T 70.1 / ISO 4762)

This is the DIN 912 / GB/T 70.1 / ISO 4762 socket head cap screw product page. DIN 912 is the German standard, GB/T 70.1 is the Chinese standard, and ISO 4762 is the international standard — all three refer to the same socket head cap screw. We supply to GB/T 70.1 as the primary standard, and take DIN 912 and ISO 4762 as equivalent standards for quoting. A DIN 912 inquiry is supplied to GB/T 70.1, with dimensions confirmed on order.

A socket head cap screw is driven through a hexagon socket in a cylindrical head. The head is low and can sit flush in a counterbore, so it is used where space is tight and where high strength and repeated assembly/disassembly are required (machine tools, dies, fixtures, mechanical assembly). Selection points: (1) installation space and counterbore — the head diameter dk and head height k set the counterbore diameter and depth, so confirm them against your assembly drawing; (2) torque transfer — the hexagon socket transmits high tightening torque at a low head height; (3) strength class — 8.8 (carbon steel) and 12.9 (alloy steel) are the classes we supply, with 12.9 offering a nominal tensile strength of 1200 MPa for high-stress joints.

Sizes made to order cover M4–M24; carbon steel 8.8 (zinc plated), alloy steel 12.9 (black oxide), stainless A2-70 (304) and A4-70 (316L, plain). Unit weights are geometry-based estimates.

Threading follows nominal length: short screws are fully threaded, longer screws keep an unthreaded grip under the head, and the thread length b is set by the standard per diameter and nominal length. Our catalog weight geometry uses a thread-length model of b = 2d+6 (length up to 125 mm), 2d+12 (length over 125 mm and up to 200 mm) and 2d+25 (length over 200 mm), capped at the nominal length; the final thread length is confirmed against your drawing on order.

For the matching hex key size, see our hex key size chart.