drill collar

Drill Collars are manufactured from AISI 4145H or 4145H modified steel, and are supplied in the "as rolled" surface finish condition. Alternative surface finishes can be provided.
Trepanning and Heat treatment:
The downhole motors manufactured in Chinese mainland have been selling in more than 20 oilfields in China as well as in USA, India, Thailand, Philippines, Iran and Russia.
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	≥758	≥965	≥13	285~341	≥54
7~12	≥689	≥930

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

• 
• 
•