FES telescopic Kelly bars are manufactured both in friction with 3, 4, 5, or 6 elements and interlocking type with 3, 4 or 5 elements for some special requirements. For common application, the external diameter is designed to be in universal dimension, such as 273mm, 299mm, 340mm, 377mm, 406mm, 419mm, 440mm, 470mm, 508mm, etc. High strength steel tube material is procured and duly heat-treated before production, which enables the Kelly bars to work well under maximum torque. Kelly lock and guides inside Kelly joints are made in highly wear-resistant material for a prolonged life. Special tooling is set up to ensure the straightness of tubes during welding process.
Producing process:
