Socket head cap screws are made of high-strength alloy steel with black oxide or zinc plating for good corrosion resistance. Their cylindrical head features a precision hexagon socket that allows the wrench to fit tightly, ensuring even force distribution and preventing cam-out. These screws are ideal for machinery assembly where space is limited or a flush surface is required. Square nuts have a regular hexahedral shape with larger side contact area than hex nuts. When inserted into a matching square recess, they resist rotation due to their sharp edges, preventing spinning during tightening. Used together, the socket head cap screw and square nut are especially suitable for wooden furniture, simple machine frames, and quick-positioning assembly applications.