M20x1.5 HSS Two-Step Tap Set

Precision-engineered two-piece tap set for M20x1.5 metric thread creation. Both taps are forged from M2 high speed steel, hardened to HRC 62–64 and finished with black oxide for rust resistance and low-friction operation. Overall length: 160 mm; shank diameter: 12 mm; thread length: 110 mm; tolerance grade: 0.014 mm per ISO 2857-1. Weight: approx. 185 g each. The set implements a proven two-stage process: the taper tap cuts the first 7–10 threads with progressive engagement, easing entry and minimising radial force; the plug tap completes the remaining thread form with tighter pitch control and improved flank finish. This division of labour reduces operator effort, prevents tap breakage and yields threads with uniform minor diameter and consistent helix angle — essential for load-bearing joints. Straight flutes ensure chips exit axially without twisting or binding, particularly important in vertical or overhead tapping positions. Use with standard tap wrenches on securely clamped workpieces. Pilot hole must be drilled to 18.5 mm Ø for steel (18.7 mm for aluminium). Apply cutting fluid regularly — sulphur-chlorinated oil recommended for steel; light mineral oil for non-ferrous metals. Avoid excessive pressure once full thread engagement is achieved — let the tap cut naturally.