Metric Reduced Shank HSS Taps DIN 376

Most taps are supplied with no surface treatment. They are referred to as ‘Bright Finish’. These taps are mainly for use on non-ferrous materials, or steels that do not cold weld. Bright finish taps are therefore suitable for all hand operations, where speeds

TITANIUM NITRIDE (Tin) This is a gold coloured coating only a few microns thick which is not metallic so reduces the chance of cold welding. It is applied by vapour deposition using special purpose machines. It imparts to the tool a surface hardness of around 80-85 Rockwell. It also imparts a good abrasive resistance and subsequent decrease in friction between the tool and the work piece. This can allow tapping at higher speeds. Suitable for most stainless steels. The process can increase the price of a tap significantly. When the tap is reground the coating will be removed. This coating is more appropriate to Fluteless taps than steam tempering and nitriding. are too low for cold welding to occur, and for most machine operations

DIN 376 and 374 These are European standard taps that are dimensionally different to the standard ISO 529 UK types. They are generally longer and have reduced shanks as do Nut Taps. Basically DIN 376 are for standard coarse threads, and DIN 374 for fine threads. A third type DIN 371 is available. These have bigger shanks, so are not really classed as long reach.