Non-Mag Drilling Collars
Non-magnetic drill collars manufactured from premium alloys for MWD/LWD tool accuracy in directional drilling.
Magnetically Clean for Survey Precision
Galip’s non-magnetic drill collars are machined from high-purity, galling-resistant austenitic stainless steel. They provide a magnetically clean environment to ensure absolute precision for MWD and LWD directional surveys.
Non-Magnetic Drill Collar Specifications
Precision-machined from premium austenitic stainless steel with certified magnetic permeability ratings. Custom sizes and connections are available to meet your directional drilling requirements.
Detailed Technical Specifications
| NC23-31 | OD 79.4 mm | Bore 31.8 mm | Length 9150 mm | Shoulder guide angle diameter 76.2 mm |
|---|---|
| NC26-35 | OD 88.9 mm | Bore 38.1 mm | Shoulder guide angle diameter 82.9 mm |
| NC31-41 | OD 104.8 mm | Bore 50.8 mm | Shoulder guide angle diameter 100.4 mm |
| NC35-47 | OD 120.7 mm | Bore 50.8 mm | Shoulder guide angle diameter 114.7 mm |
| NC38-50 | OD 127 mm | Bore 57.2 mm | Shoulder guide angle diameter 121 mm |
| NC44-60 | OD 152.4 mm | Bore 57.2 mm | Length 9150 or 9450 mm | Shoulder guide angle diameter 144.5 mm |
| NC44-60 (large bore) | OD 152.4 mm | Bore 71.4 mm | Shoulder guide angle diameter 144.5 mm |
| NC46-62 | OD 158.8 mm | Bore 57.2 mm | Shoulder guide angle diameter 149.2 mm |
| NC46-62 (large bore) | OD 158.8 mm | Bore 71.4 mm | Shoulder guide angle diameter 150 mm |
| NC46-65 | OD 165.1 mm | Bore 57.2 mm | Shoulder guide angle diameter 154.8 mm |
| NC46-65 (large bore) | OD 165.1 mm | Bore 71.4 mm | Shoulder guide angle diameter 154.8 mm |
| NC46-67 | OD 171.4 mm | Bore 57.2 mm | Shoulder guide angle diameter 159.5 mm |
| NC50-67 | OD 171.4 mm | Bore 71.4 mm | Shoulder guide angle diameter 159.5 mm |
| NC50-70 | OD 177.8 mm | Bore 57.2 mm | Shoulder guide angle diameter 164.7 mm |
| NC50-70 (large bore) | OD 177.8 mm | Bore 71.4 mm | Shoulder guide angle diameter 164.7 mm |
| NC50-72 | OD 184.2 mm | Bore 71.4 mm | Shoulder guide angle diameter 169.5 mm |
| NC56-77 | OD 196.8 mm | Bore 71.4 mm | Shoulder guide angle diameter 185.3 mm |
| NC56-80 | OD 203 mm | Bore 71.4 mm | Shoulder guide angle diameter 190.1 mm |
| 6-5/8REG | OD 209.6 mm | Bore 71.4 mm | Shoulder guide angle diameter 195.7 mm |
| NC61-90 | OD 228.6 mm | Bore 71.4 mm | Shoulder guide angle diameter 212.7 mm |
| 7-5/8REG | OD 241.3 mm | Bore 76.2 mm | Shoulder guide angle diameter 223.8 mm |
| NC70-97 | OD 247.6 mm | Bore 76.2 mm | Shoulder guide angle diameter 232.6 mm |
| NC70-100 | OD 254 mm | Bore 76.2 mm | Shoulder guide angle diameter 237.3 mm |
| 8-5/8REG | OD 279.4 mm | Bore 76.2 mm | Shoulder guide angle diameter 266.7 mm |
| Magnetic Permeability | < 1.005 u (certified) |
|---|---|
| Material Type | Austenitic stainless steel (300 series) |
| Alloy Composition | High-purity, low-carbon grade |
| Heat Treatment | Solution annealed for optimal non-magnetic properties |
| MWD/LWD Compatibility | Fully compatible with all magnetic survey tools |
| Tensile Strength | >= 75,000 PSI (517 MPa) |
|---|---|
| Yield Strength | >= 30,000 PSI (207 MPa) |
| Elongation | >= 40% in 2 inches |
| Hardness | Max 22 HRC |
| Galling Resistance | Enhanced anti-galling properties |
| Corrosion Resistance | Superior SCC resistance in H2S environments |
| OD RangeCustomizable | 3 1/2" to 11" (standard sizes) |
|---|---|
| Length RangeCustomizable | 15 ft to 31 ft (standard) |
| Bore DiameterCustomizable | Custom bored to specification |
| Connection TypeCustomizable | NC, IF, API Reg (all threads available) |
| Surface FinishCustomizable | Slick or spiral grooved |
| Dimensional Tolerance | API 7-1 specification compliance |
| API Specification | API 7-1 Non-Magnetic Drill Collar standard |
|---|---|
| Material Certification | Full MTR included |
| Magnetic Testing | Individual permeability testing and certification |
| Dimensional Inspection | 100% inspection with certified report |
| Thread Inspection | Gauged and inspected per API 7-1 |
| Traceability | Unique serial number with full documentation |
Engineered for Survey Accuracy
Premium materials and precision manufacturing ensure minimal magnetic interference for accurate directional measurements.
Low Magnetic Permeability
Certified magnetic permeability below 1.005 ensures minimal interference with survey tools.
Corrosion Resistance
Premium austenitic stainless steel provides strong SCC resistance in harsh environments.
Precision Bored
Tight bore tolerances ensure smooth fluid flow and improved hydraulic performance.
API Certified
Full API 7-1 compliance with certified reports and inspection records.
Material Discipline & Inspection Workflow
Non-mag collar performance depends on metallurgy, dimensional control, and documented inspection, so this section highlights the manufacturing and QA signals behind the finished product.
Magnetically Clean Material, Machined for Survey Accuracy
Galip non-mag collars are specified around low permeability, galling resistance, and stable mechanical properties. Precision boring and finishing help maintain clean ID flow paths while supporting the MWD or LWD string above the bit.
Directional drilling accuracy depends on a collar body that stays magnetically clean while still handling torque, axial load, and corrosive field conditions.
Inspection Records, Traceability & Final Release
Material certificates, magnetic permeability checks, dimensional inspection, and threaded-connection verification all support final release. Those checks matter just as much as the alloy itself when the collar will be used around survey-sensitive tool strings.
Certified MTR packages and inspection reports simplify customer acceptance and later traceability.
Workshop and test-stand controls support final gauging, handling, and release documentation.
Custom OD, bore, and thread combinations can be built without losing the QA trail required by drilling programs.
Buyer Questions
Non-Mag Drill Collar Buyer Q&A
Non-mag drill-collar buyers usually focus on magnetic cleanliness, metallurgy, dimensional stability, and the inspection package that proves the collar is ready for directional drilling service.
Why are non-mag drill collars specified instead of standard drill collars?
They create a magnetically cleaner section in the BHA so MWD and survey tools can produce more reliable directional data. That matters when drilling accuracy, steering confidence, and tool protection all depend on limiting magnetic interference.
What quality checkpoints should buyers review before ordering non-mag collars?
Review the material grade, permeability target, bore and OD tolerance, connection specification, and final inspection scope. Helpful background includes how non-mag drilling tools support directional accuracy, why non-magnetic drilling collars matter in oilfield service, and how directional support hardware affects the broader drilling package.
Can Galip supply custom dimensions or connection combinations?
Yes. Custom OD, bore, and thread combinations can be discussed as long as the finished product and inspection path still align with the drilling program, traceability expectations, and release criteria on your side.
What should be included in the inquiry before quotation?
Send the required OD, bore, connection, length, material or permeability target, and the intended directional application. If there are release-document or inspection expectations, include those early so the proposal reflects the real acceptance path.
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