API Boreback Box Connection API stress relieve groove pin connection Cold Rolling Thread roots Phosphate coated connections 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 Standard Pressed Steel Thread Protectors. Cast Steel Lifting Bail Thread Protectors upon request. 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. Dongguan Huayuan Electronic Technology Co., Ltd , https://www.siliconefactory-oem.com
These drill collars are designed for high-performance drilling applications and are suitable for a wide range of oil and gas operations. Each specification is carefully engineered to ensure durability, strength, and compatibility with various drilling systems. If you need further details or have specific requirements, please feel free to contact our technical team for assistance.
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
Options
Protection
Mill Test Certificates
Common drill collar sizes are listed in the table below. These products are manufactured according to API specifications, including API 7/7-1 and API RP7G where applicable. Customization options are available to meet specific requirements, such as additional features and proprietary connections from leading manufacturers.