How to use self – drilling self – tapping screw?

Self-tapping screws are generally fingertip screws, coarse teeth, hard wood screws, aluminum alloy, plastic screws.

A special kind of self – tapping screw used to thread metal holes is called a tap.

Self-tapping screws are used for non-metal or soft metal, without bottom hole and tapping; Self-tapping screw is pointed, so that it can “self-tapping”; Ordinary screws are flat head, uniform thickness.

Self-tapping screw means:

Drilling holes for the hole without tapping thread, the screw and the general is different, the head is pointed, the tooth spacing is relatively large.

And no chip wire tapping is a bit like, can not tap teeth directly screw in, metal and plastic usually use this method.

It can be in the consolidated material, by its own thread, will be consolidated body “tap – drill, squeeze, pressure” out of the corresponding thread, so that it closely cooperate with each other.

Usage of self-drilling and self-tapping screw:

1. After the self-drilling self-tapping screw is hit into the hole on the ground or wall, tighten the nut on the self-drilling self-tapping screw with a wrench, and the screw goes out. The outer metal sleeve does not move, so the big head under the screw will open the metal sleeve, so that it is full of the whole hole, at this time, the self-drilling self-tapping screw can not be pulled out.
2. Self-drilling and self-tapping screw is a special thread connector used to fix the air duct support, suspension and bracket on the wall, floor and column. It is composed of countersunk head bolt, expansion pipe, flat washer, spring pad and hexagon nut. When using, it is necessary to use the impact drill (hammer) in the fixed body on the corresponding size of the hole, and then the bolt, expansion pipe installed into the hole, screw the nut can make the bolt, expansion pipe, installation parts and fixed body between the expansion and tightening into one.
3. Self-drilling self-tapping screw is composed of a screw and an expansion pipe and other components. The tail of the screw is conical, the large diameter of the cone is greater than the inner diameter of the expansion pipe. Moreover, a large positive pressure is formed on the outer surface of the expansion tube, and the Angle of the cone is very small, so that the friction self-lock is formed between the wall, the expansion tube and the cone, and then the fixing effect is achieved.
4. The spring pad on the self-drilling self-tapping screw is a standard part, because its opening is staggered and elastic, so it is called the spring washer. The role of the spring washer is to use the sharp sharp Angle of the wrong mouth to pique the nut and the pad to prevent the nut from loosening.