How to use stud bolt

This kind of double head with self tapping screw is generally used in furniture.

1. Fix two nuts on the normal thread end and tighten them alternately. Then screw the upper nut with a wrench and screw the self tapping screw into the matrix until it can not be screwed（ This method is also used when this screw is screwed out, but the lower nut is screwed out with a wrench.)

2. Then use two spanners to screw the nut in the opposite direction at the same time, loosen the nut, so that the two nuts can be backed out.

3. Pass the fastener (generally with through hole) through the normal thread end, add gasket, and tighten the nut normally.

說一下為什么要用這種螺絲，這種螺絲一般用在需要經常拆卸的場合，因為自攻端一旦拆出，就不好用了，所以采用這種雙頭螺絲避免拆出自攻螺絲端，需要拆卸時只要把螺母擰下，就能拆掉后裝上去的件兒，防止了自攻端受到破壞。