... bit1.Sizes range from 3 7/8" to 26" , normal sizes consist of 5 7/8", 6", 6 1/2", 7 1 ... /2", 8 1/2", 9 1/2", 9 5/8 ... ", 9 7/8", 12 1/4",13 5/8", 14 3/4 ... ", 15 1/2", 16", 17 1/2",22", 26", etc. .2.Covers almost all IADC codes .3 ... will decrease the cost of project. 3 7/8''Steel Tooth Bit