... cutting structure durability 4.Fast delivery steel tooth roller bitProduct Description:Size from 3 7/8" to ... and bearing life. 3> Bearing Structure High precision roller bearing with two thrust faces. Ball lock the ... ” ), 101.6mm, 114mm, 118mm, 120mm, 127mm(5” )130.1mm(5 1/8” ), 133.3mm (5 1/4” ... models:Steel tooth(IADC code)111, 121, 131117, 124, 126, 127, 136, 137211, 311216, 217, 227TCI(IADC code)415, ...