Genuine Durocast 30* Thread forming screw for Light Alloys
Series 20216 Type: 1552
The 30 deg. Flank angle and recessed core diameter of these thread forming screws for light alloys and highly filled plastics provides optimum performance. The large difference between the drive in torque and ultimate stripping torque is achieved due to the narrow 30 degree flank angle of the thread. The screw does not require high drive in torque as it displaces only half the material of a conventional screw form. The greater penetration achieved by the low profile flank form ensures a greater surface area contact with the material therefore increasing frictional retention which directly results in high stripping and break-loose torque values. The additional space provided by the recessed core eliminates galling during thread forming. Elimination of thread cutting means a chipless assembly, there is no need for cleaning the threads. A high repeatability is guaranteed as the conical blunt point provides optimum start location for thread forming and provides preliminary location prior to thread engagement on restarts, therefore eliminating cross threading.