Shanxi Huanjie Petroleum Drilling Tools Co., Ltd.

Standard Size for Drill Collars

Drill collar number and connection

Outside Diameter

Inside Diameter

Length (mm)

Bevel Diameter

Ref. Bending Strength
Ratio

mm

in

mm

in

NC26-35 (2 3/8 IF)

88.9

3 1/2

38.1

1- 1/2

9150

82.9

2.42:1

NC31-41 (2 7/8IF)

104.8

4 1/8

50.8

2

9150

100.4

2.43:1

NC46-62 (4 IF)

158.8

6 1/4

71.4

2- 13/16

9150 or 9450

150.0

2.63:1

NC46-65 (4 IF)

165.1

6 1/2

71.4

2- 13/16

9150 or 9450

154.8

3.05:1

NC46-67 (4 IF)

171.4

6 3/4

57.2

2- 1/4

9150 or 9450

159.5

3.18:1

NC50-67 (4 1/2 IF)

171.4

6 3/4

71.4

2- 13/16

9150 or 9450

159.5

2.37:1

NC50-72 (4 1/2 IF)

184.2

7 1/4

71.4

2- 13/16

9150 or 9450

169.5

3.12:1

NC56-77

196.8

7 3/4

71.4

2- 13/16

9150 or 9450

185.3

2.70:1

6 5/8 REG

209.6

8 1/4

71.4

2- 13/16

9150 or 9450

195.7

2.93:1

7 5/8REG

241.3

9 1/2

76.2

3

9150 or 9450

223.8

2.81:1

NC70-100

254.0

10

76.2

3

9150 or 9450

237.3

2.81:1