... seal 3)used to drill low compressive strength API 8 1/2" Kingdream Newest IADC 437 TCI tricone bit1)used ... Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4",17 1/2", etc.HJ ... uses the most advanced sealing technology in the world, i.e. the metal face seal (MFS). It can perform ... HJ527G, HJ537G, HJ547G, HJ617G, HJ627G, HJ637G, HJ737G,etc. API 8 1/2" Kingdream Newest IADC 437 TCI tricone bit