Product Information
Drill Collar is mainly used for providing drill bit with required drilling pressure, ensuring pull force transmitted to drill pipe and centralize the drill bit. According to API Spec 7-1 specifications, the material quality is 4145H that's after heat-treatment, thread hardening treatment and phosphating to better antiseize. It also can be produced upon customers' requirements.
The parameter of drill collar according to API Spec 7-1 specifications.
| Drill Collar Thread |
Outside Diameter D |
Inside Diameter d |
Length |
Chamfer Diameter |
Reference Bending Strength Ratio |
| L |
Df |
| mm |
in |
mm |
in |
mm |
mm |
| NC31-41(27/8IF) |
104.8 |
4 1/8 |
50.8 |
2 |
9140or9450 |
100.4 |
2.43:1 |
| NC35-47 |
120.7 |
4 3/4 |
50.8 |
2 |
9140or9450 |
114.7 |
2.58:1 |
| NC38-50(31/2IF) |
127 |
5 |
57.2 |
2 1/4 |
9140or9450 |
121 |
2.38:1 |
| NC44-60 |
152.4 |
6 |
57.2 |
2 1/4 |
9140or9450 |
144.5 |
2.49:1 |
| NC44-60 |
152.4 |
6 |
71.4 |
2 13/16 |
9140or9450 |
144.5 |
2.84:1 |
| NC44-62 |
158.8 |
6 1/4 |
57.2 |
2 1/4 |
9140or9450 |
149.2 |
2.91:1 |
| NC46-62(4IF) |
158.8 |
6 1/4 |
71.4 |
2 13/16 |
9140or9450 |
150 |
2.63:1 |
| NC46-65(4IF) |
165.1 |
6 2/4 |
57.2 |
2 1/4 |
9140or9450 |
154.8 |
2.76:1 |
| NC46-65(4IF) |
165.1 |
6 2/4 |
71.4 |
2 13/16 |
9140or9450 |
154.8 |
3.05:1 |
| NC46-67(4IF) |
171.4 |
6 3/4 |
57.2 |
2 1/4 |
9140or9450 |
159.5 |
3.18:1 |
| NC50-67(41/2IF) |
171.4 |
6 3/4 |
71.4 |
2 13/16 |
9140or9450 |
159.5 |
2.37:1 |
| NC50-70(41/2IF) |
177.8 |
7 |
57.2 |
2 1/4 |
9140or9450 |
164.7 |
2.54:1 |
| NC50-70(41/2IF) |
177.8 |
7 |
71.4 |
2 13/16 |
9140or9450 |
164.7 |
2.73:1 |
| NC50-72(41/2IF) |
184.2 |
7 1/4 |
71.4 |
2 13/16 |
9140or9450 |
169.5 |
3.12:1 |
| NC56-77 |
196.8 |
7 3/4 |
71.4 |
2 13/16 |
9140or9450 |
185.3 |
2.70:1 |
| NC56-80 |
203.2 |
8 |
71.4 |
2 13/16 |
9140or9450 |
190.1 |
3.02:1 |
| 6 5/8REG |
209.6 |
8 1/4 |
71.4 |
2 13/16 |
9140or9450 |
195.7 |
2.93:1 |
| NC61-90 |
228.6 |
9 |
71.4 |
2 13/16 |
9140or9450 |
212.7 |
3.17:1 |
Audited Supplier 
){kind=link}
){kind=link}