Self-drilling self-tapping screws have many different head types, and many people do not know that the head types are different, and their roles are also different. There are several commonly used head types in the internationally recognized self-tapping screw head types, each of which has a different function:
1. Flat head: It can replace the new design of round head and mushroom head. The head has a low diameter and a large diameter. The outer circumference of the head is connected with the high-shaped edge that indicates the characteristics, so that it can drive the high-strength torque. There is a slight difference in type.
2. Round head: It is the most commonly used head type in the past.
3. Top column head: The diameter of the standard flat dome column head is smaller than the round head, but it is higher due to the groove depth. The smaller diameter increases the pressure acting on a small area, which can be tightly combined on the flange and heightened Surface layer. They can be successfully applied to the cavity of the inner hole due to the heading in the drilling mold set to ensure concentration.
4. Dome wide-side head: Because the under-head cut restrains and weakens the abrasion of the wire components, it is most commonly used in electrical appliances and tape recorders. It provides a more adequate bearing surface for the middle-low head type. Attractive design type.
5. Big round head: also known as elliptical top and wide side head, it is a low-shaped, cleverly designed large-diameter head. When the combined tolerance of the additional effect allows, it can be used to cover metal plate holes with larger diameters. It is also recommended to use a flat head instead.
6. Hexagon socket head: a knot with a wrench head height and hexagon head size. The hexagonal shape is completely cold-formed by the reverse hole mold, and there is an obvious depression on the top of the head.
7. Hexagon socket washer head: like the standard hexagon socket head type, but at the same time there is a washer surface at the base of the head to protect the completion of the assembly to avoid damage to the wrench. Sometimes the function of things is far more important than appearance.
8. Hexagonal head: This is a standard type of torque acting on the hexagonal head. It has the feature of trimming sharp corners to close to the tolerance range. It can be recommended for general commercial use, and can also be applied to various standard patterns and various thread diameters. Because of the necessary second process, it is more expensive than the general hexagonal socket.
9. Flat-top countersunk head: The standard angle is 80~82 degrees, which is used for fasteners whose surfaces need to be tightly joined. The bearing surface can provide good centering.
10. Flat-round countersunk head: This head type is similar to the standard flat-top countersunk head, but it is more widely used. In addition, a round and neat upper surface is more attractive in design.