Drill Collar
Drill Collars are manufactured from AISI 4145H or 36CrNiMo4 modified steel, and are supplied in the "as rolled" surface finish condition. Alternative surface finishes can be provided.

Material: AISI 4145H or AISI 4145H Modified
Type: slick and spiral
Length:
10¡¯~32¡¯
OD size range: 3-1/8"~12"
Connection Thread: IF FH REG
Trepanning and Heat treatment:
Drill collars are trepanned and drifted to API Spec 7. Full-length heat-treatment processes ensure that mechanical properties meet or exceed API Spec 7 requirements. A hardness range of 285-341, Brinell Hardness and Charpy gV h notch minimum impact strength of 40 ft-lb at 70OF are guaranteed one inch below the surface.
Mechanical Property |
OD
inch |
Yield strength 0.2Mpa |
Tensile strength b Mpa |
Elongation 4% |
Hardness
(brinell) |
IMPACT VALUE
(CHAPPY-V) |
3 1/8~6 3/4 |
¡Ý758 |
¡Ý965 |
¡Ý13 |
285~341 |
¡Ý54 |
7~12 |
¡Ý689 |
¡Ý930 |