After the threads have been formed, the tap is retracted in a helical movement from the hole via the grooves. The finished threads are interrupted by two helical grooves offset by 180 deg.

DORMER PRAMET added a new option to its offering for high-end threading: the Dormer Shark E894 is a high-performance HSS-E thread forming tap suitable for both through and blind holes in a wide range ...

A new tooling system produces threaded holes in all types of sheet metal, eliminating the need for secondary tapping operations or additional fasteners. Developed by Mate Precision Tooling, Anoka ...

Screw threads are used for a variety of purposes and applications in the machine tool industry. They are used to hold or fasten parts together (screws, bolts and nuts), and to transmit motion (the ...

Ray Ollis Jr., Design of Metric Machine and Tapping Screws, SAE Transactions, Vol. 86, Section 3: 770404–770718 (1977), pp. 1853-1889 ...