... ,TCI bit,button bit Sizes range from 3 7/8" to 26" . Reliable bearing and lubrication system Detailed Product Description Tungsten carbide ... ,TCI bit,button bit Sizes range from 3 7/8" to 26" . Reliable bearing and lubrication system1.Cutting Structure The durability of ... ,622,632,73210 5/8269.8622,63212 1/4311.1622.632 API 12 1/4'' tricone rock bit for oil drilling and water drilling