Materials of the Non-magnetic drill collars are from chrome manganese, low carbon obtained by combining a proprietary chemical analysis and a rotary hammer process. The material is resistant to stress corrosion cracking, with high machine ability and no tendency to galling.
Magnetic permeability (when MPS=1105/4Nm) relative max μr:1.010.
Magnetic field gradient (hot spots) max: B 0.05micro tesla/100mm.
Magnetic field gradient (hot spots) max: B 0.05micro tesla/100mm.
Sel.
|
OD
|
ID
|
L mm
|
Mm bending strength ratio
|
Bending strength ratio
|
||
Mm
|
In
|
Mm
|
In
|
||||
NC21-31
|
79.4
|
3 1/8
|
31.8
|
1 1/4
|
9150
|
76.2
|
2.57:1
|
NC26-35
|
88.9
|
3 1/2
|
38.1
|
1 1/2
|
9150
|
82.9
|
2.42:1
|
NC31-41
|
104.8
|
4 1/8
|
50.8
|
2
|
9150 or 9450
|
100.4
|
2.43:1
|
NC35-47
|
120.7
|
4 3/4
|
50.8
|
2
|
9150 or 9450
|
114.7
|
2.58:1
|
NC38-50
|
127.0
|
5
|
57.2
|
2 1/4
|
9150 or 9450
|
121.0
|
2.38:1
|
NC44-60
|
152.4
|
6
|
57.2
|
2 1/4
|
9150 or 9450
|
144.5
|
2.49:1
|
NC44-60
|
152.4
|
6
|
71.4
|
2 13/16
|
9150 or 9450
|
144.5
|
2.84:1
|
NC44-62
|
158.8
|
6 1/4
|
57.2
|
2 1/4
|
9150 or 9450
|
149.2
|
2.91:1
|
NC46-62
|
158.8
|
6 1/4
|
71.4
|
2 13/16
|
9150 or 9450
|
150.0
|
2.63:1
|
NC46-65
|
165.1
|
6 1/2
|
57.2
|
2 1/4
|
9150 or 9450
|
154.8
|
2.76:1
|
NC46-65
|
165.1
|
6 1/2
|
71.4
|
2 13/16
|
9150 or 9450
|
154.8
|
3.05:1
|
NC46-47
|
171.4
|
6 3/4
|
57.2
|
2 1/4
|
9150 or 9450
|
159.5
|
3.18:1
|
NC50-67
|
171.4
|
6 3/4
|
71.4
|
2 13/16
|
9150 or 9450
|
159.5
|
2.37:1
|
NC50-70
|
177.8
|
7
|
57.2
|
2 1/4
|
9150 or 9450
|
164.7
|
2.54:1
|
NC50-70
|
177.8
|
7
|
71.4
|
2 13/16
|
9150 or 9450
|
164.7
|
2.73:1
|
NC50-72
|
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
|
NC56-80
|
203.2
|
8
|
71.4
|
2 13/16
|
9150 or 9450
|
190.1
|
3.02:1
|
6 5/8 REG
|
209.6
|
8 1/4
|
71.4
|
2 13/16
|
9150 or 9450
|
195.7
|
2.93:1
|
NC61-90
|
228.6
|
9
|
71.4
|
2 13/16
|
9150 or 9450
|
212.7
|
3.17:1
|
7 5/8 REG
|
241.3
|
9 1/2
|
76.2
|
3
|
9150 or 9450
|
223.8
|
2.81:1
|
NC70-97
|
247.6
|
9 3/4
|
76.2
|
3
|
9150 or 9450
|
232.6
|
2.57:1
|
NC70-100
|
254.0
|
10
|
76.2
|
3
|
9150 or 9450
|
237.3
|
2.81:1
|
8 5/8REG
|
279.4
|
11
|
76.2
|
3
|
9150 or 9450
|
266.7
|
2.84:1
|
8 5/8REG
|
355.6
|
14
|
76.2
|
3
|
9150 or 9450
|
266.7
|
2.84:1
|