Pan head self-tapping screw is a screw with a pan head (round head with a washer) and self-tapping capability.
The pan head has a large diameter, a slightly flat or convex top, and usually includes a washer underneath. This design provides a large contact surface and clamping force, while evenly distributing pressure and preventing the screw head from sinking into the material being fastened. It is commonly used in situations where aesthetics are required or large holes need to be covered.
Common head types include Phillips head, slotted head, and hex head (internal or external hex) to accommodate different driving tools.
Self-tapping: The screw's threads are specially designed for fastening softer materials such as plastics, thin metal sheets, and wood. It taps itself by rotating.
Materials: Commonly used are C1022A carbon steel and stainless steel (such as 304, 316).
Carbon steel is often surface-treated to increase rust resistance and aesthetics, such as galvanizing (white zinc, color zinc), nickel plating, blackening, and Dacromet coating.
Usage steps: When the screw is driven to rotate by a drill or screwdriver:
Its sharp guide tip first positions and penetrates the material.
As it rotates, the sharp threads, like a tap, squeeze and cut corresponding grooves in the material being fastened.
The screw is tightly engaged with the material through the newly formed threads, while the head presses against the connected parts, achieving a fastening effect.
