Specifications – Standard
Sizes, Bores, and Connections
Drill Collar Conn. Size & Type |
Min. OD | Bore | Length | Bending Strength Ratio*** |
Drill Collar Wt. |
(in.) | (in.) | (ft.) | (lb.) | ||
2 3/8 REG | 3 1/8 | 1 1/4 | 31 | 2.75:1 | 653 |
2 7/8 PAC | 3 1/8 | 1 1/4 | 31 | 2.16:1 | 653 |
NC 26 (2-3/8 IF) | 3 1/2 | 1 1/2 | 31 | 2.42:1 | 828 |
NC 31 (2-7/8 IF) | 4 1/8 | 2 | 31 | 2.43:1 | 1077 |
NC 38 (3-1/2 IF) | 4 3/4 | 2 1/4 | 31 | 1.91:1 | 1448 |
NC 38 (3-1/2 IF) | 5 | 2 1/4 | 31 | 2.38:1 | 1650 |
NC 46 (4 IF) | 6 1/4 | 2 1/4 | 31 | 2.38:1 | 2811 |
NC 46 (4 IF) | 6 1/2 | 2 1/4 | 31 | 2.76:1 | 3077 |
NC 46 (4 IF) | 6 1/2 | 2 13/16 | 31 | 3.07:1 | 2842 |
NC 50 (4-1/2 IF) | 6 1/2 | 2 1/4 | 31 | 1.89:1 | 3077 |
NC 50 (4-1/2 IF) | 6 1/2 | 2 13/16 | 31 | 2.03:1 | 2842 |
NC 50 (4-1/2 IF) | 6 3/4 | 2 1/4 | 31 | 2.20:1 | 3350 |
NC 50 (4-1/2 IF) | 6 3/4 | 2 13/16 | 31 | 2.54:1 | 3115 |
NC 56 | 8 | 2 13/16 | 31 | 3.02:1 | 4640 |
6-5/8 REG | 8 | 2 13/16 | 31 | 2.60:1 | 4640 |
6-5/8 REG | 8 1/4 | 3 | 31 | 2.99:1 | 4888 |
7 5/8 REG | 9 1/2 | 3 | 31 | 2.82:1 | 6723 |
7-5/8 REG.** | 9 1/2 | 3 | 31 | 2.82:1 | 6723 |
8-5/8 REG.** | 11 | 3 | 31 | 2.84:1 | 9272 |
** Low torque face *** Ratio of box to pin section modulus – See API RP7G for details Note: Other sizes and connections are available as well as any other optional features listed below |
Drill Collar Features & Options
Drill Collar OD | Elevator Recess OD (ER) (in) |
Slip Recess OD (SR) (in) |
Elevator Recess Radius (R) (in) |
4 3/4 | 4 1/4 | 4 3/8 | 1/8 |
5 | 4 1/2 | 4 5/8 | 1/8 |
6 1/4 | 5 5/8 | 5 3/4 | 1/8 |
6 1/2 | 5 7/8 | 6 | 1/8 |
6 3/4 | 6 | 6 1/4 | 3/16 |
8 | 7 1/4 | 7 1/2 | 3/16 |
8 1/4 | 7 1/2 | 7 3/4 | 3/16 |
9 1/2 | 8 5/8 | 9 | 1/4 |
11 | 10 1/8 | 10 1/2 | 1/4 |
These features are not recommended for collars with OD below 4-3/4″ |
Specifications – Non-Mag
Sizes, Bores, and Connections
Drill Collar Conn. Size & Type |
Min. OD | Bore | Length | Bending Strength Ratio*** |
Drill Collar Wt. |
(in.) | (in.) | (ft.) | Per 31 ft | ||
NC 38 (3-1/2 IF) | 4 3/4 | 2 1/4 | 31 | 1.92:1 | 1448 |
NC 38 (3-1/2 IF) | 4 3/4 | 2 11/16 | 31 | 2.32:1 | 1270 |
NC 38 (3-1/2 IF) | 5 | 2 1/4 | 31 | 2.38:1 | 1650 |
NC 38 (3-1/2 IF) | 5 | 2 11/16 | 31 | 2.89:1 | 1472 |
NC 46 (4 IF) | 6 1/2 | 2 13/16 | 31 | 3.07:1 | 2842 |
NC 46 (4 IF) | 6 1/2 | 3 1/4 | 31 | 3.59:1 | 2622 |
NC 50 (4 1/2 IF) | 6 3/4 | 2 13/16 | 31 | 2.37:1 | 3115 |
NC 50 (4 1/2 IF) | 6 3/4 | 3 1/4 | 31 | 2.62:1 | 2895 |
6-5/8 REG | 8 | 2 13/16 | 31 | 2.60:1 | 4640 |
6 5/8 REG | 8 | 3 1/4 | 31 | 2.75:1 | 4420 |
Note: Other sizes and connections are available as well as any other optional features listed below. |