Hi - Lo Plastic Tapping Screws

The Hi-lo fastener, with its unique thread form, improves fastener performance in a broad range of automotive grade plastics. This fastener is designed with a double lead, consisting of a high and a low thread. The high thread is sharper than a conventional thread, having a 30� included angle as compared to the conventional 60� included angle. The low thread has the 60� included angle and a height that is 40% to 50% of the high thread height.

The superior performance of the Hi-Lo fastener increases product quality and decreases costs. The 30� included angle of the high thread form reduces radial or bursting pressure over that generated by a conventional 60� included angle thread form. Boss cracking in plastic is dramatically reduced and smaller diameter bosses can often be specified.

The Hi-lo screw thread configuration has a smaller minor diameter than a conventional screw. The high threads make a deeper cut into the material leaving a greater volume of material between the threads. There is also a greater amount of material in contact with the high, sharp thread and the axial shear area is increased. All of this contributes to greater resistance to pull-out and stronger fastening.

The threads of the Hi-Lo Plus fasteners have a unique bi-level shape that directs the displaced material upward, flowing it around the threads.

Heads on Hi-Lo Plus fasteners are made to standard ANSI/ASME dimensions.

In forming mating heads in the work piece, the unique Hi-Lo Plus Screw accommodates the displaced material between the widely spaced high threads, actually increasing thread engagement while minimizing outward pressure.

The 30� included angle of the high thread displaces less material when it is driven into the mating plastic, and therefore, requires lower driving torques. A greater amount of material remains between the high threads, increasing the stripping torque. Low driving torque and high stripping torque provides maximum protection against stripping failures.

.136 Hole Diameter

.136 Hole Diameter