Interlocking Kelly bars are used with piling rigs for drilling in dense sand and gravel and weak to strong rock. The Interlocking Kelly bars manufactured by KR can be fully locked by mechanical locking system on each section. Kelly bars can be equipped with specially designed springs or pressure plates for shock absorbing purpose.

Friction Kelly bar is another type of kelly bar, which the external key is composed of 3 or 6 wear -resistant strips without lock recesses. This kelly bar can form pressure force when the kelly bar is rotary. can produce peripheral force and the rotary passing down the pressure force, can produce the friction force. This kelly bar has the advantage of operating sample, drilling deep, but with less pressure transmission.

Usually full lock kelly bar is composed of three weld-on ribs continuous concave and convex keys. It especillay for hard ground and frozen oil formation layer.When drilling process, the advantage is force uniform, not easy to stick pipe, particular to improve work efficiency.

Usually Customized kelly bar is formed by Interlocking kelly bar pipe, Friction kelly bar pipe, Full lock ribs kelly bar pipe or other mix-lock types based on your specific projects complicated formation needs.