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Size

(in)

O.D

(mm)

I.D.

(in)

Code Thread Length

(mm)

Weight

(kg)

3 1/8 79.4 1-1/4 NC23-31 NC23 9140 298
3 1/2 88.9 1-1/2 NC26-35 NC26 9140 364
4 1/8 104.8 2 NC31-41 NC31 9140/9450 474/490
4 3/4 120.6 2 NC35-47 NC35 9140/9450 674/697
5 127 2-1/4 NC38-50 NC38 9140/9450 725/749
6 152.4 2-1/4 NC44-60 NC44 9140/9450 1125/1163
6 152.4 2-13/16 NC44-60 NC44 9140/9450 1022/1056
6 1/4 158.8 2-1/4 NC44-62 NC44 9140/9450 1237/1279
6 1/4 158.8 2-13/16 NC46-62 NC44 9140/9450 1134/1172
6 1/2 165.1 2-1/4 NC46-65 NC46 9140/9450 1352/1398
6 1/2 165.1 2-13/16 NC46-65 NC50 9140/9450 1249/1291
6 3/4 171.4 2-1/4 NC46-67 NC46 9140/9450 1471/1521
7 177.8 2-1/4 NC50-70 NC50 9140/9450 1597/1651
7 177.8 2-13/16 NC50-70 NC50 9140/9450 1494/1545
7 1/4 184.2 2-13/16 NC50-72 NC50 9140/9450 1625/1680
7 3/4 196.8 2-13/16 NC56-77 NC56 9140/9450 1895/1960
8 203.2 2-13/16 NC56-80 NC56 or 6- 5/8REG 9140/9450 2040/2109
8 1/4 209.6 2-13/16 6-5/8REG 6-5/8REG 9140/9450 2188/2263
9 228.6 2-13/16 NC61-90 NC61 9140/9450 2658/2748
9 1/2 241.3 2-13/16 7-5/8REG 7-5/8REG 9140/9450 2954/3054
9 3/4 247.6 3 NC70-97 NC70 9140/9450 3127/3234
10 254 3 NC70-100 NC70 9140/9450 3308/3421
11 279.4 3 8-5/8REG 8-5/8REG 9140/9450 4072/4210
Mechanical properties:

<7 inch Drill Collar: Yield Strength≥758MPa, Tensile Strength≥965MPa, Four times elongation ≥13%, Impact energy Ak≥54J (Single impact work≥47J, Average≥54J), Hardness range: 285HB~341HB

7inch Drill Collar: Yield Strength≥689MPa, Tensile Strength≥931MPa, Four times elongation≥13%, Impact energy Ak≥54J (Single impact work≥47J, Average≥54J), Hardness range 285HB~341HB

Drill collar can be customized as per customer’s design.

Drill Collars are integral heavy-wall joints that are manufactured from a solid bar of modified alloy steel. The solid bars are quenched and tempered to obtain the required mechanical properties, then trepanned, drifted and threaded. All drill collars are heat-treated with hardness within 285 to 341 BHN, which are guaranteed one inch below the surface of the pipe.

Lake Petroleum could supply slick type drill collar, spiral drill collar and Non-magnetic drill collar (NMDC).

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Why choose Lake Petro?
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Methods of Payment & Quality Control
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What’s the order procedure?

Buyer’s Guide

Please send us your inquiry with detail item description or with Model number. If there is no packing demand we take it as our regular exported standard packing. We will offer you an order form for filling. We will recommend you the most suitable model according to information you offered.

We can give you really high quality products with competitive price. We have a better understanding in Chinese market, with us your money will be safe.

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Lake Petro is located in Dongying City, which is famous for Shengli Oilfield and the largest manufacturing hub of petroleum equipment in China. Following the principle of “quality first, science and technology innovated, people oriented”, every Lake Petro person is sparing no effort to provide the customers with best products and services. Our products are based on advanced production line and testing equipment, our products are designed and manufactured according to certification of API, ISO, GOST, etc.