Drill Collars Specifications

Jan 22, 2024

Common drill collar sizes are shown in the table below.

Products are manufactured to API specifications. 7/7-1 and API RP7G (if applicable), can be customized to your requirements with additional features and proprietary connections from leading manufacturers.

Drill Collar Connection	Drill Collar Diameter(in)	Bore Diameter(in)	Length(ft)	Linear Weight (Approx.) (lb/ft)	Displacement (Open End) (US gal/ft)	Bending Strength Ratio
NC 23-31	3-1/8	1-1/4	30	22.00	0.337	2.57:1
NC 26-35 (2-3/8 IF)	3-1/2	1-1/2	30	26.70	0.408	2.42:1
NC 31-41 (2-7/8 IF)	4-1/8	2	30 or 31	33.65	0.515	2.43:1
NC35-47	4-3/4	2	30 or 31	46.81	0.716	2.58:1
NC 38-50 (3-1/2 IF)	5	2-1/4	30 or 31	53.29	0.815	2.38:1
NC 44-60	6	2-1/4	30 or 31	82.61	1.264	2.49:1
NC 44-60	6	2-13/16	30 or 31	75.90	1.161	2.84:1
NC 44-62	6-1/4	2-1/4	30 or 31	90.52	1.385	2.91:1
NC 46 -62 (4IF)	6-1/4	2-13/16	30 or 31	83.81	1.282	2.63:1
NC 46 -65 (4IF)	6-1/2	2-1/4	30 or 31	99.52	1.522	2.76:1
NC 46-65 (4IF)	6-1/2	2-13/16	30 or 31	92.81	1.420	3.05:1
NC 46-67 (4IF)	6-3/4	2-1/4	30 or 31	108.52	1.600	3.18:1
NC 50-70 (4IF)	7	2-1/4	30 or 31	117.52	1.798	2.54:1
NC 50 -70 (4IF)	7	2-13/16	30 or 31	110.77	1.694	2.73:1
NC 50-72 (4IF)	7-1/4	2-13/16	30 or 31	119.81	1.833	3.12:1
NC 56-77	7-3/4	2-13/16	30 or 31	139.90	2.140	2.70:1
NC 56-80	8	2-13/16	30 or 31	150.81	2.307	3.02:1
6-5/8 REG	8-1/4	2-13/16	30 or 31	161.81	2.472	2.93:1
NC 61-90	9	2-13/16	30 or 31	195.81	2.995	3.17:1
7-5/8 REG	9-1/2	3	30 or 31	217.00	3.319	2.81:1
NC 70 -97	9-3/4	3	30 or 31	230.00	3.518	2.57:1
NC 70-100	10	3	30 or 31	242.97	3.717	2.81:1
8-5/8 REG	11	3	30 or 31	299.00	4.574	2.84:1
Standard Features		API Boreback Box Connection API stress relieve groove pin connection Cold Rolling Thread roots Phosphate coated connections
Options		Spiral grooved or Non-Spiral (Slick Type) Type of Hardband and Hardband configuration Elevator and Slip recesses or Slip Recess only Other type of connections to meet specific needs
Protection		Standard Pressed Steel Thread Protectors. Cast Steel Lifting Bail Thread Protectors upon request.
Mill Test Certificates		Issued in accordance with API 7/7-1 and API RP7G specifications. Third Party Inspection can be performed on request at buyer’s care and expense.