Kelly bushing is a necessary tool for
drilling, by matching with rotary square to drive kelly pipe. Through the
rotation of four rolls, the friction between rolls and kelly pipes is reduced
to extend service life. Change different rollers to match with different
squares and hexagonal kelly pipes and connect with different rotary tables. Two
transmission styles (square and pinconnect) are available. The product is
designed and manufactured according to api spec 7k “specification for drill
equipment”.