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High-Quality China 4145H Non-Mag Drill Collar - Reliable Suppliers & Factory Manufacturing Standards

Drill collars play a crucial role in the drilling process by effectively transferring torque from the top drive or rotary table to the drill bit while minimizing energy loss. Designed to provide optimal weight on bit (WOB), they enhance drilling efficiency and stabilize the bottom hole assembly (BHA) by preventing bending and whipping during rotation. This function significantly reduces vibrations and wear on downhole tools, leading to improved drilling accuracy and extended equipment lifespan, Our drill collars are manufactured in China from high-strength AISI 4145H modified alloy steel and non-magnetic materials. As a trusted supplier, we ensure that all our products strictly adhere to API Spec 7-1, GOST, and NS-1 standards. Each collar undergoes rigorous quenching and tempering processes to optimize mechanical properties, ensuring durability and reliability even in the most challenging drilling conditions. Choose our factory for reliable drill collars that meet the highest industry standards

Product Details

Drill Collar Testing

All drill collar materials undergo both chemical composition and mechanical property testing prior to machining.

Each collar is subject to 100% ultrasonic testing (UT) and magnetic particle inspection (MPI) to detect internal and surface defects.

Hydrostatic testing is performed to verify pressure integrity and seal performance.

Drill Collar Features

Made from 4145H modified alloy steel and non-magnetic materials, suitable for drill collars, spiral drill collars, lifting subs, and crossover subs.

Manufactured strictly in accordance with API Spec 7-1, GOST, and NS-1 quality standards.

TAKELO offers proprietary double shoulder connections and other premium thread designs, with optional cold-rolled thread roots, phosphatizing, nitriding, or tungsten alloy plating to enhance performance and longevity.

Optional services include various types of hardbanding and internal plastic coating (IPC) based on customer specifications.

All drill collars are equipped with advanced thread root cold-rolling and optional phosphatizing treatment to enhance fatigue resistance and minimize galling during make-up and breakout cycles. Thread protectors are used throughout handling and transportation.

Optional surface treatments such as tungsten alloy plating, nitriding, and internal plastic coating (IPC) are available to improve corrosion resistance in high-salinity or sour gas environments, extending service life in harsh drilling conditions.

Drill Pipe Specifications

Size	O.D(mm)	I.D.(mm)	Code	Thread	Length(mm)
3 1/8	79.4	31.8(1-1/4)	NC23-31	NC23	9140
3 1/2	88.9	38.1(1-1/2)	NC26-35	NC26	9140
4 1/8	104.8	50.8(2)	NC31-41	NC31	9140/9450
4 3/4	120.6	50.8(2)	NC35-47	NC35	9140/9450
5	127	57.2(2-1/4)	NC38-50	NC38	9140/9450
6	152.4	57.2(2-1/4)	NC44-60	NC44	9140/9450
6	152.4	71.4(2-13/16)	NC44-60	NC44	9140/9450
6 1/4	158.8	57.2(2-1/4)	NC44-62	NC44	9140/9450
6 1/4	158.8	71.4(2-13/16)	NC46-62	NC44	9140/9450
6 1/2	165.1	57.2(2-1/4)	NC46-65	NC46	9140/9450
6 1/2	165.1	71.4(2-13/16)	NC46-65	NC50	9140/9450
6 3/4	171.4	57.2(2-1/4)	NC46-67	NC46	9140/9450
7	177.8	57.2(2-1/4)	NC50-70	NC50	9140/9450
7	177.8	71.4(2-13/16)	NC50-70	NC50	9140/9450
7 1/4	184.2	71.4(2-13/16)	NC50-72	NC50	9140/9450
7 3/4	196.8	71.4(2-13/16)	NC56-77	NC56	9140/9450
8	203.2	71.4(2-13/16)	NC56-80	NC56/6-5/8REG	9140/9450
8 1/4	209.6	71.4(2-13/16)	6-5/8REG	6-5/8REG	9140/9450
9	228.6	71.4(2-13/16)	NC61-90	NC61	9140/9450
9 1/2	241.3	76.2(2-13/16)	7-5/8REG	7-5/8REG	9140/9450
9 3/4	247.6	76.2(3)	NC70-97	NC70	9140/9450
10	254	76.2(3)	NC70-100	NC70	9140/9450
11	279.4	76.2(3)	8-5/8REG	8-5/8REG	9140/9450

Frequently Asked Questions

What materials are used to manufacture the drill collars?

Our drill collars are made from 4145H modified alloy steel and non-magnetic materials. They are suitable for standard drill collars, spiral drill collars, lifting subs, and crossover subs.

What quality standards do your drill collars comply with?

They are manufactured strictly in accordance with API Spec 7-1, GOST, and NS-1 quality standards to ensure top-tier performance and reliability.

How do you test the drill collars for internal or surface defects?

Each collar is subjected to 100% ultrasonic testing (UT) and magnetic particle inspection (MPI) to detect any internal and surface defects. Additionally, hydrostatic testing is performed to verify pressure integrity.

What surface treatments are available for harsh drilling environments?

We offer optional surface treatments such as tungsten alloy plating, nitriding, and internal plastic coating (IPC). These improve corrosion resistance in high-salinity or sour gas environments, extending the service life.

How is galling minimized during make-up and breakout cycles?

All drill collars feature advanced thread root cold-rolling and optional phosphatizing treatment. This significantly enhances fatigue resistance and minimizes galling during operational cycles.

Do you provide custom or premium thread designs?

Yes, TAKELO offers proprietary double shoulder connections and other premium thread designs tailored to customer specifications, along with optional hardbanding services.

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