How do you choose a drill when you want to screw a hole with a torch?
It is a self tapping screw, usually a drill with a diameter of 3 millimeters. However, this screw is not strong here, it is better to use core pulling rivets.
You can go to the nearest hardware store to buy a self drilling screw, the screw angle and six countersunk head (that is, you said no head screws) two, the screw head with drill, then the middle thread length is 250 mm! It is specially used for insulating layer
Pay attention to when you use it1, flashlight to hold steady, do not swing;2 、 the flashlight should be perpendicular to the object that needs to be drilled (keep 90 degrees);3, control the rotation speed first slow and then normal (if there is this function);In 4, before drilling, first make a small object in the drilling process, in order to guarantee.
This is a self tapping screw, usually with a diameter of 3 millimeters of drill, but here this screw is not strong, it is best to use the core rivets
