Hardened Flat washers
Hardened Flat washers are used under bolt heads or nuts to increase the bearing area and to offer hardness so that the nut or bolt can be rotated without distortion of the bearing surface. Hardened Flat washers are used to give tightness to a joint, to prevent leakage, and especially to distribute pressure under the head of a nut or bolt. Globally sold F436 and F436M American specification hardened washer and DIN 6916 and 6340 washers are commercial spec washers. For the construction market, there is a range of hardened washers to both BS EN14399-6/9 and 15048.