Cross recessed pan head screw, spring washer and flat washer assembly is a common fastener combination, is widely used in a variety of need to be fixed and connected occasions.
This kind of assembly is widely used in steel structure, railway and highway Bridges, boiler steel structure, industrial plant, high-rise civil building, especially in the case of high strength connection,
When installing, usually needs to use a special electric wrench, there are two socket heads, one is set on the hexagon body of the nut, the other is set on the dodecagon body of the pan head screw, to ensure the accuracy and efficiency of installation.