TCI 437 Soft formation TCI Tricone bits The 437 tci bits are used to drill low compressive strength very soft formation tci bits maximize the use of both conical and chisel tungsten carbide inserts of large diameters and high projection. This cutting structure design combined with maximum cone offset ,results in high bit penetration rates.the deep intermesh of cutter rows prevents bit bailing in sticky formations. TCI 517 medium formation TCI Tricone bits The 517 features aggressive chisel tungsten carbide inserts on the heel rows and inner rows this design provides a fast drilling rate and added cutting structure durability in medium to medium hard formations the HSN rubber o-ring provides adequate sealing for bearing durability. TCI 617 TCI tricone bits 617 features robust chisel tungsten carbide inserts on the heel row and conical on the inner rows .this design provides a fast drilling rate and added cutting structure durability in medium to medium hard formations . the HSN rubber o-rin provides adequate sealing for bearing durability . TCI 637 can be used to drill hard and abrasive formations wear –resistant tungsten carbide inserts are used in the outer rows to prevent loss of bit gauge. maximum numbers of hemispherical-shaped inserts are used in all rows to provide cutter durability and long life.