Machine relieved and ground form gear hobs are manufactured to cover the range from .5 to 30 modules & 64 DP to 0.8 DP confirming to DIN 3968, BS 2062. Chain sprocket hobs are usually supplied in un ground form to cut roller chain sprockets to din, American standard with the range from 1/4" to 3" pitch or 5mm to 76.2 mm pitch.