HSS-G screw taps are suitable for machinable raw materials up to 900 N/mm². The design in HSS-E for hard to machine raw materials up to 1200 N/mm² and vapourised hand screw taps are particularly suited to wear-resistant steels up to 1400 N/mm².
The taps can be distinguished from their thread leads and marking. Pre-cutters (rougher) are marked on their shank with one and middle cutter (intermediate) with two rings. The finished cutter does not carry a ring and is generally not marked.
Rougher = 6-8 Thread pitch
Intermediate = 4-5 Thread pitch
Finisher = 2-3 Thread pitch
It is recommended that the finishing cutter should only be used for trimming damaged threads. The rougher, intermediate and finisher can be ordered separately.