Square Kelly and Hexagonal Kelly Transit the torsional energy from the rotary table to the bit in the bottom of the hole and bear the hanging load weight.

1) Materials: 4145H modified alloy steel

2) Standard: API Spec. 7-1, GOST and NS-1.

3) Hardness range: 285 to 341 BHN

4) Manufacturing: Min. impact value of 54 Joules as per ASTM A 370 Charpy-V, these values are guaranteed one inch

    below the surface.

5) Quenched and tempered along full length.

6) Kelly bars: Inspected by an ultrasonic unit over their full length and full section.

7) The wall Thickness of each flat of the drive section is verified ultrasonically.

8) Connections: fitted with pressed steel thread protectors on both ends

9) Shipping: with steel scabbard for marine transportation.