for ISO metric fine thread DIN 13
grade of fit ISO 2 (6H)
Group 1 - For machining in steels and other materials with low and medium strengh and good chipping.
Group 2 - For machining in tough materials and stainless steels.
Group 3 - For machining in short chipping and hard materials.
Group 4 - For machining in soft materials with long chipping.