Square and Hexagonal Kelly
 Square and Hexagonal Kelly
1. Specification:
　　Square Kelly： 2-1/2” 2-7/8” 3” 3-1/2” 4-1/4” 5-1/4”
Hexagonal Kellys：3” 3-1/2” 4-1/4” 5-1/4”

2. Description:
　The Kelly is made from AISI4145H alloy steel, whole Kelly are hardened, with hardness up to 285-341BHN and charpy impact value≧54J. We can guarantee the physical properties 1 inch under the pipe body surface. The inside dimension and connections are made and inspected according to API Standard.
The whole Kelly and cross section are inspected by ultrasonic unit, the thickness of drive section is also under ultrasonic inspection.

3. Function: Kelly is the drive section of whole drill stem, the Kelly are made according to SY/T6509-2000 or API SPEC.7-1