CSC Production Square Kelly and Hexagonal Kelly
Kelly is a critical component located at the top of the drill string, available in both square and hexagonal designs. In rotary drilling operations, the kelly connects with the square bushing and the rotary bushing, transmitting the surface rotational torque to the drill pipe and driving the drill bit. It also supports the weight of the entire drill string. When using turbine or mud motor drilling systems, the kelly helps bear the weight of the drill string and counteracts the torque generated during the process.
Introduction
Continental Steel Co., Ltd. (CSC) offers high-quality square and hexagonal kellys manufactured strictly according to API Spec 7-1 standards. The materials used are AISI 4145H modified alloy steel, fully heat-treated to achieve a Brinell hardness range of 285–341 and a minimum Charpy impact value of 40 ft-lbs. Each kelly bar undergoes ultrasonic inspection along its full length and cross-section to ensure quality and reliability.
Parameter Table
| Size (in) | Top Connection (LH) | Bottom Connection | I.D. (in) | Drive Section (in) | ||||
| Standard O.D. (in) | Optional O.D. (in) | Square O.D. (in) | Hex. O.D. (in) | Square | Hex. | A | B | |
| 2-1/2 | 6-5/8 REG 7-3/4 | 4-1/2 REG 5-3/4 | NC26 | / | 1-1/4 | / | 3-2/7 | / |
| 3 | 6-5/8 REG 7-3/4 | 4-1/2 REG 5-3/4 | NC31 4-1/8 | NC26 3-3/8 | 1-3/4 | 1-1/4 | 4 | 3-3/8 |
| 3-1/2 | 6-5/8 REG 7-3/4 | 4-1/2 REG 5-3/4 | NC38 4-3/4 | NC31 4-1/8 | 2-1/4 | 1-3/4 | 4-1/2 | 4 |
| 4-1/4 | 6-5/8 REG 7-3/4 | 4-1/2 REG 5-3/4 | NC46 6-1/4 | NC38 4-3/4 | 2-4/5 | 2-1/4 | 5-4/7 | 4-4/5 |
| 6-5/8 REG 7-3/4 | 4-1/2 REG 5-3/4 | NC50 6-3/8 | NC38 4-3/4 | 2-4/5 | 2-1/4 | 5-4/7 | 4-4/5 | |
| 5-1/4 | 6-5/8 REG 7-3/4 | / | 5-1/2 FH 7 | NC46 6-1/4 | 3-1/4 | 3 | 7 | 6 |
| 6-5/8 REG 7-3/4 | / | NC56 7 | NC50 6-3/8 | 3-1/4 | 3-1/4 | 7 | 6 | |
| 6 | 6-5/8 REG 7-3/4 | / | / | 5-1/2 FH 7 | / | 3-1/2 | / | 6-4/5 |
| 6-5/8 REG 7-3/4 | / | / | NC56 7 | / | 3-1/2 | / | 6-4/5 | |
Our kelly products are designed for durability and performance in demanding drilling environments. Whether you're working on conventional rotary rigs or advanced directional drilling systems, our square and hexagonal kellys are engineered to meet the highest industry standards. With a wide range of sizes and connection types available, we can provide the right solution for your specific application. Choose CSC for reliable, high-quality kelly products that support your drilling operations efficiently and safely.
Automotive Parts,Honda Crv Caliper,Twin Air Compressor Mounting,Engine Exhaust System
Dandong Haichuan Machinery Co., Ltd. , https://www.ddhccasting.com