Drill collar is mainly used to provide bit weight to drill bit so that drill piipe is in tension. Especially drill collar can keep drill bit centralized and hole tradck by large rigidity. Spiral drill collar is used to reduce contact area with hole so as to avoid efficienty bit stricking from differential pressure. Our drill colars are manufactured as per API spec. 7.
Drill collar thread type OD ID Length (mm)
NC23-31 mm in mm in
NC26-35 ( 23/8 IF ) 79.4 3 1/8 31.8 11/4 9150
NC31- 41(27/8 IF) 88.9 31/2 38.1 11/2 9150
NC35-47 104.8 41/8 50.8 2 9150
NC38-50(31/2 IF) 120.7 43/4 50.8 2 9150
NC44-60 127.0 5 57.2 21/4 9150
NC44-60 152.4 6 57.2 21/4 9150 (or) 9450
NC44-62 152.4 6 71.4 2 13/16 9150 (or) 9450
NC46-62(4 IF) 158.8 61/4 57.2 21/4 9150 (or) 9450
NC46-65(4 IF) 158.8 61/4 71.4 2 13/16 9150 (or) 9450
NC46-67(4 IF) 165.1 61/2 57.2 2 13/16 9150 (or) 9450
N50-67(4 1/2 IF) 165.1 61/2 71.4 2 13/16 9150 (or) 9450
NC50-70(4 1/2 IF) 171.4 63/4 57.2 2 13/16 9150 (or) 9450
NC50-70(4 1/2 IF) 171.4 63/4 71.4 2 13/16 9150 (or) 9450
NC50-72(4 1/2 IF) 177.8 7 57.2 2 1/4 9150 (or) 9450
NC50-70(4 1/2 IF) 177.8 7 71.4 2 13/16 9150 (or) 9450
NC50-72(4 1/2 IF) 184.2 71/4 71.4 2 13/16 9150 (or) 9450
NC56-77 196.8 73/4 71.4 2 13/16 9150 (or) 9450
NC56-80 203.2 8 71.4 2 13/16 9150 (or) 9450
6 5/8 REG 209.6 81/4 71.4 2 13/16 9150 (or) 9450
NC61-90 228.6 9 71.4 2 13/16 9150 (or) 9450
7 5/8 REG 241.3 9 1/2 76.2 3 9150 (or) 9450
NC70-97 247.6 93/4 76.2 3 9150 (or) 9450
NC70-100 254.0 10 76.2 3 9150 (or) 9450
8 5/8 REG 279.4 11 76.2 3 9150 (or) 9450