Adopt the advanced technology of 6-key design in the world and standard modular design.Equipped with advanced processing facilities, workmanship and manufacturing equipments, Suny kelly bar enjoys a low weight, high strength, high straightness of single bar, thinner tube, smaller inter-tube distance and good abrasion resistance.The raw materials are either imported from Germany like the high abrasion resistance materials, or from Chinese top manufacturer such as the seamless steel tube with alloy. All the tubes made in China are specially made seamless alloy tube, which guarantees the accuracy of the sizes, location, physical properties and easy welding. The small-diameter tubes undergo reheat treatment. The friction kelly bar can be used under full torque.All the outer keys have undergone special heat treatment; therefore, they possess higher hardness, higher flexibility and excellent welding properties, which provide higher abrasion resistance to the keys.Friction Kelly bars are used with piling rigs for drilling in silt, clay and less dense sand and gravel. The Friction Kelly bars manufactured by Suny are un-lockable with drive keys on each section. Kelly bars can be equipped with specially designed springs or pressure plates for shock absorbing purpose