| 摘要 |
A screw adapted for use with thin sheet metal. The screw has a threaded shank and a head with an integral flange. The flange has both radial and axial undulations which increase the amount of torque required to strip the screw. The undulations are formed at the outer edge of the flange and on the under surface of the flange and are adapted to engage a workpiece upon threaded advancement of the screw.
|
