Alpha HSS Hand Taps are precision manufactured in Europe to ISO529 standards. HSS Hand Taps are general purpose taps suitable for hand and machine operation, and are suitable for production use. 2N Tolerance for optimum thread fit that balances fastener performance, manufacturing, economy and convenience. Suitable for use in Steel, Aluminium, Copper, Brass etc. Always use lubricant. Click here for our range. INTERMEDIATE taps have a lead of four threads and are used in most general purpose applications. Alpha Intermediate taps can be identified by the two rings on the shaft near the driving square. Diameter: 20mm Pitch: 2.5mm Overall length: 95mm Shaft Diameter: 16mm Drive Square: 12mm Tapping Drill Size: 17.50mm