Drill collar
Type of thread
O.D
I.D
Length
Beveling
diameters
Df
Bending strength ratio for reference
mm
in
NC31-41(27/8IF)
104.8
4 1/8
50.8
2
9150
100.4
2.43:1
NC35-47
120.7
4 3/4
114.7
2.58:1
NC38-50(31/2IF)
127
5
57.2
2 1/4
121
2.38:1
NC44-60
152.4
6
9150 or 9450
144.5
2.49:1
71.4
2 13/16
2.84:1
NC44-62
158.8
Apr-61
149.2
2.91:1
NC46-62(4IF)
150
2.63:1
NC46-65(4IF)
165.1
Feb-61
154.8
2.76:1
3.05:1
NC46-67(4IF)
171.4
Apr-63
159.5
3.18:1
NC50-67(41/2IF)
2.37:1
NC50-70(41/2IF)
177.8
7
164.7
2.54:1
2.73:1
NC50-72(41/2IF)
184.2
Apr-71
169.5
3.12:1
NC56-77
196.8
Apr-73
185.3
2.70:1
NC56-80
203.2
8
190.1
3.02:1
65/xREG″
209.6
Apr-81
195.7
2.93:1
NC61-90
228.6
9
212.7
3.17:1
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