DIN571 hexagon head wood screws have higher torque force than pan head and countersunk head tapping screws, better control of torque required for rotation, and higher strength after combination. The engineering standard definition of thread rolling self-tapping screws is higher and more specific than that of forming or cutting self-tapping screws, making thread rolling self-tapping screws a real "construction" fastener.

There are coarse rod and full thread, coarse rod products have screw and thread, one end of the screw forms a pointed head, the tooth distance is relatively large, and the chip free tap is similar to, can be directly screwed in without tapping teeth, the lead of the thread is larger than the mechanical thread, the thread length is greater than or equal to 0.6 of the specification length, the thread Angle is 600, the product specification M4 -- M20, etc.