Binding screw with cross hole for embedded seat nut
This is a screw that incorporates a washer used to prevent loosening and to avoid the sinking of the seat surface. The screw threads are roll-formed with the washer in place, ensuring that the washer does not come off the screw. This eliminates the hassle of inserting the washer, prevents it from falling out, and helps improve work efficiency. The head is shaped like a combination of a pan and a truss, with a diameter about 1.2 times larger than that of a pan head screw of the same nominal size. It is sometimes used when the head diameter is too large for a truss. Like the pan head, it is a small screw that can be used widely. A typical example of its use is the fastening of wires inside a power plug.