8 1/2'' insert tooth drill bit in good quality

Softformation TCI tricone bits:
Thesoft formation TCI tricone bits are used to drill low compressive strength, verysoft formations. This bit maximized to use of both conical and chisel tungstencarbide inserts of large diameters and high projection. This cutting structuredesign, combined with maximum cone offset, results in high bit penetrationrates. The deep intermesh of cutter rows prevents bit bailing in stickyformations.

Mediumformation TCI tricone bits:
Themedium formation TCI tricone bits features aggressive chisel tungsten carbideinserts on the heel rows and inner rows. This design provides a fast drillingrate and added cutting structure durability in medium to medium hard formations. The HSN rubber O-ring provides adequate sealing for bearingdurability.

Hardformation TCI tricone bits:
Thehard formation TCI tricone bits can be used to drill hard and abrasiveformations. Wear resistance tungsten carbide inserts are used in the outer rowsto prevent loss of bit gauge. Maximum numbers of hemispherical shaped insertsare used in all rows to provide cutter durability and long life.

Mediumhard formation TCI tricone bits:
Themedium hard formation TCI tricone bits features robust chisel tungsten carbideinserts on the heel row and conical on the inner rows. This design provides afast drilling rate and added cutting structure durability in medium to mediumhard formations. The HSN rubber O-ring provides adequate sealing for bearingdurability.