Petroleum Well Drilling Collar (API / SY/T5144)

All the drill collars(Type A Column, Type B Spiral, Type C Non-megnatic) are made to the API Standard and SY/T5144 Standard. The material for Types A and B is AISI4145H Cl-Mo Alloy steel, milled or forged, whose composition is well controled.
Type C is made of the stainless steel alloy whose megnetic conduction rate is very low. This material is forged with strict chemical annalisis, hence the good low rate of megnetic conduction and the fine mechanical performance.
All the drill collars(Type A Column, Type B Spiral, Type C Non-megnatic) are made to the API Standard and SY/T5144 Standard. The material for Types A and B is AISI4145H Cl-Mo Alloy steel, milled or forged, whose composition is well controled.
Type C is made of the stainless steel alloy whose megnetic conduction rate is very low. This material is forged with strict chemical annalisis, hence the good low rate of megnetic conduction and the fine mechanical performance.
All the drill collars(Type A Column, Type B Spiral, Type C Non-megnatic) are made to the API Standard and SY/T5144 Standard. The material for Types A and B is AISI4145H Cl-Mo Alloy steel, milled or forged, whose composition is well controled.
Type C is made of the stainless steel alloy whose megnetic conduction rate is very low. This material is forged with strict chemical annalisis, hence the good low rate of megnetic conduction and the fine mechanical performance.
Before leaving the plant each drill collar has to pass the strict examination by the special examiner, and the result is recorded in the examination letter. In the marking channel of each drill collar, the API mark, the serial number, the outside diameter, inside diameter and the fitting type and size can all be got according to the consumer's requirement.
The outside diameter may vary between 3 1/8'' and 11'', while the length may be between 10 and 31 feet.