These formulas aer also applicable to slots on the cylinder and otherquadraprism.

Then by taking the regular square prism as an example, the machining error is analyzed, and the relationship among the length of the lathe tool, the work dimension and the tolerance is obtained.

Therefore, the overthread screw tap can be matched with a pneumatic wrench having regular hexagonal holes via insertion, and the overthread screw tap has the advantage of high work efficiency.