Drill Collar Number

O.D.

I.D.

mm

in

mm

in

NC23-31

79.4

3 1/8

31.8

1 1/2

NC26-35(2 3/8 IF)

88.9

3 1/2

38.1

1 1/2

NC31-41(2 7/8 IF)

104.8

4 1/8

50.8

2

NC35-47

120.6

4 3/4

50.8

2

NC38-50(3 1/2 IF)

127.0

5

57.2

2 1/4

NC44-60

152.4

6

57.2

2 1/4

NC44-60

152.4

6

71.4

2 13/16

NC44-62

158.8

6 1/4

57.2

2 1/4

NC46-62(4IF)

158.8

6 1/4

71.4

2 13/16

NC46-65(4IF)

165.1

6 1/2

57.2

2 1/4

NC46-65(4IF)

165.1

6 1/2

71.4

2 13/16

NC46-67(4IF)

171.4

6 3/4

57.2

2 1/4

N50-67(4 1/2 IF)

171.4

6 3/4

71.4

2 13/16

NC50-70(4 1/2 IF)

177.8

7

57.2

2 1/4

NC50-70(4 1/2 IF)

177.8

7

71.4

2 13/16

NC50-72(4 1/2 IF)

184.2

7 1/4

71.4

2 13/16

NC56-77

196.8

7 3/4

71.4

2 13/16

NC56-80

203.2

8

71.4

2 13/16

6 5/8 REG

209.6

8 1/4

71.4

2 13/16

NC61-90

228.6

9

71.4

2 13/16

7 5/8 REG

241.3

9 1/2

76.2

3

NC70-97

247.6

9 3/4

76.2

3

NC70-100

254

10

76.2

3

8 5/8 REG

279.4

11

76.2

3