BLACK RING Machine Tap Set, DIN 371/376, HSS-E, M 3 - 12 

cast iron GG, spheroidal graphite iron GGG - MagnesiuAlloys - for through and blind holes surface treatment nitrided: - increased surface hardness - high abrasion resistance - improved anti-friction properties Thread type: metric ISO-thread DIN 13 Norm: DIN 371/376 Material: HSS-E