Share how to use the screw plug
The screw plugs are mostly used after installation, and the surface of the parts cannot have bulges. The parts to be fastened have two thicknesses. The so-called thick means that the thickness of the parts being fastened is greater than the thickness of the head of the plug. After the screws are tightened, some of the threads of the screws do not enter the threaded holes. In this case, the screw plug can definitely be tightened. There is usually a situation where the thickness of the parts being fastened is less than the height of the head of the screw plug, which is common in sheet metal parts in mechanical equipment, such as the connection between the hinge of the chassis and the door and the box body; the sheet metal cover of the equipment connection to equipment, etc. Due to the small thickness of the part, the tightened sheet metal part, the screw hole is completely a conical hole, in this case, when the screw plug is tightened, the screw head is not the tapered surface to press the sheet metal part, Instead, the bottom of the screw head and the top of the threaded hole are squeezed. Although it feels that the screw is tightened, the sheet metal part is stuck instead of being pressed. In this case, although it feels that the screw is tightened, the sheet metal The piece is indeed not tightened. This is a very common situation.
Let’s talk about the reasons for processing: the head cone of the screw plug has a 90° conical angle, and the apex angle of the newly bought drill is usually 118°-120°. Some workers who lack training do not know this angle is poor, often Directly use a 120° drill to ream the hole, which results in that it is not the conical surface of the head that struggles when tightening the plug, but a line at the bottom of the screw head, which is one of the reasons why the so-called plug cannot be tightened.
