Self-tapping screw head types and uses

Head type:

Fasteners made increases end shape of the bearing surface of the part. On thread forming and the thread cutting since attack screws (since attack nail),, flat-topped buried (Flat Countersunk), Oblate buried (Oval Countersunk), Pan head (Pan), six angle and the six angle China silk head (Hex and Hex washer Head) most important, this five species head type accounted for has all since attack screws almost 90% above, using since attack screws (since attack nail) should first consider this

Five heads.

Another five species other type type for flat-topped concave bearing surface (Flat Undercut), flat-topped whole margin (Flat Trim), Oblate concave bearing surface (Oval Undercut), Oblate whole margin (Oval Trim) and the cylindrical head (gang Hill Fillister) for compared secondary head type, and mushrooms head (Truss), round head (Round) and the 100 degrees flat-topped buried for new design by not take, cover its function can for other head type by replaced, Pan head can replaced mushrooms head and the round head , 82 degree flat countersunk can replace the 100 degree flat countersunk.

Slash self tapping screws (self-tapping) heads on the choice and the same, used mainly for flat-top, flat top, Pan head, Hexagon and Hexagon washer head five.

Self drilling screws with flat-top, flat top, the first and most common hex washer head, Hexagon does not use, in fact in the process of drilling, need pressure to tighten drilling tools to support tools. with a Phillips flat-top, flat top, Pan head or hex washer head.

Although the United States national standards only 13 standard head, but still can be used with any other head for commercial purposes, such as dry wall screws using Bugle, pancakes and other special shaped head design, manufacturers can depend on other material manufacturing.

-Support or anchor fastener parts, usually handling the screw through the bearing surface. There are two basic types, flat surface (with the fastener Rod vertical) and cone-shaped bearing surface (the angle formed with the fastener rod) which

Several cases to support the loads acting on the fastener and services, besides continuing flat bearing surface to the same function, but also can be used to locate. Cone bearing surface of knot often refers to the countersunk head. Heads of the different applications, initially depends on the bearing surfaces of functions and heads the ability to transmit torque.