IS0 529 - Straight Flute Individual Sizes - Second.
Thread Forms are Class 2 medium fit tolerance. (1) Diameter and pitch not mentioned in ISO.

Sherwood HSS Taps are the general purpose option for thread cutting in most materials including steel, some stainless steels, cast irons and non-ferrous materials such as Aluminium, Brass and many others.

Manufactured with precision ground flutes for producing accurate thread forms, Sherwood Taps are available in all the popular thread forms and as straight Flute `Hand` Taps in 3 leads, Fluteless, Spiral Flute, or Spiral Point Machine Taps and also Long Series.

Sherwood Tap dimensions conform to ISO529 apart from NPT Forms which conform to ANSI 94.9. Straight Flute and Fluteless Taps are manufactured with a standard Bright Finish whereas the Machine Taps have an Oxidised Finish for best results, dissipating the heat build-up associated with these applications.