Flange Head Bolt

Flange head bolts combine the bearing area of a flange with the driving convenience of a hex head - the flange under the head distributes the clamping load over a larger area than a standard hex head bolt, reducing the risk of damage to the joint surface and providing better resistance to vibration loosening. The flange under the head provides a larger bearing surface that prevents the bolt from pulling through the joint material - this is especially important in automotive applications where the joint surface may be a softer material like aluminum or plastics. The integrated flange also eliminates the washer that a standard hex head bolt would require, reducing parts count and assembly time. 10B21 and 10B22 boron steel handle Grade 8 applications - good strength with good machinability and cost effectiveness. 4340 alloy steel provides the higher strength for Grade 10 applications where higher clamping force is required. The flange diameter and thickness are standardized per DIN 6921 or ASME B18.2.3 - the standard dimensions ensure interchangeability with other manufacturers' flange head bolts.