Non-magnetic drill collars are drill collar tools made of low-carbon high-chromium manganese alloy steel as the main material. Their core characteristics are low magnetic permeability (relative magnetic permeability μr≤1.010) and high-strength mechanical properties. This type of product achieves technical indicators such as tensile strength ≥827MPa and yield strength ≥758MPa through processes such as quenching and tempering heat treatment, and is widely used in scenarios such as oil drilling monitoring. The mainstream specifications cover an outer diameter of 16-200mm and a length of 1-6 meters, and support on-demand customization to meet the needs of different drilling rigs.
| Magnetic permeability | μr≤1.005(average value) |
| Tensile strength | ≥827MPa |
| Main materials | 15-15hs max high nitrogen steel, P530/550 non-magnetic stainless steel, manganese-chromium alloy stainless steel, monel alloy steel, N1310 low carbon alloy steel, 0Cr13Mn18Ni2MoN alloy steel |
| Connection Type | OD | ID | Length | ||
| mm | in | mm | in | (ft) | |
| NC23-31 | 79.4 | 3 1/8 | 31.8 | 1 1/2 | Available from 10 to 31 ft |
| NC26-35(2 3/8 IF) | 88.9 | 3 1/2 | 38.1 | 1 1/2 | |
| NC31-41(2 7/8 IF) | 104.8 | 4 1/8 | 50.8 | 2 | |
| NC35-47 | 120.6 | 4 3/4 | 50.8 | 2 | |
| NC38-50(31/2IF) | 127 | 5 | 57.2 | 2 1/4 | |
| NC44-60 | 152.4 | 6 | 57.2 | 2 1/4 | |
| NC44-60 | 152.4 | 6 | 71.4 | 2 13/16 | |
| NC44-62 | 158.8 | 6 1/4 | 57.2 | 2 1/4 | |
| NC44-62(4IF) | 158.8 | 6 1/2 | 71.4 | 2 13/16 | |
| NC44-65(4IF) | 165.1 | 6 1/2 | 57.2 | 2 1/4 | |
| NC44-65(4IF) | 165.1 | 6 1/2 | 71.4 | 2 13/16 | |
| NC44-67(4IF) | 171.4 | 6 3/4 | 57.2 | 2 1/4 | |
| NC50-672(41/2IF) | 171.4 | 6 3/4 | 71.4 | 2 13/16 | |
| NC50-70(41/2IF) | 177.8 | 7 | 57.2 | 2 1/4 | |
| NC50-70(41/2IF) | 177.8 | 7 | 71.4 | 2 13/16 | |
| NC50-72(41/2IF) | 184.2 | 7 1/4 | 71.4 | 2 13/16 | |
| NC56-77 | 196.8 | 7 3/4 | 71.4 | 2 13/16 | |
| NC56-80 | 203.2 | 8 | 71.4 | 2 13/16 | |
| 6 5/8 REG | 209.6 | 8 1/4 | 71.4 | 2 13/16 | |
| NC61-90 | 228.6 | 9 | 71.4 | 2 13/16 | |
| 7 5/8 REG | 241.3 | 9 1/2 | 76.2 | 3 | |
| NC70-97 | 247.6 | 9 3/4 | 76.2 | 3 | |
| NC70-100 | 254 | 10 | 76.2 | 3 | |
| 8 5/8 REG | 279.4 | 11 | 76.2 | 3 | |
