API 7-1 Drill Collar
Our mill manufactures premium, API 7-1 certified integral slick, spiral, and non-magnetic drill collars precision-machined from AISI 4145H modified forged alloy steel. We guarantee maximum structural weight-on-bit execution, rigid trepanned bore concentricity, certified thread cold rolling execution, and ultra-tough impact resistance boundaries under direct [2-Hour Rapid Quote] mill terms.
Terrified of downhole twist-offs, sudden directional tracking failures, or connection fatigue cracks while your drilling window closes in? Eliminate bottom-hole assembly fatigue risks and secure your mill-verified testing certificates immediately.
PRODUCT DETAILS
Premium API Heavy Duty Drill Collar Three-Standard Cross Matrix
| American Standard (API 7-1 / AISI) | European Standard (EN 10210 / ISO) | Japanese Standard (JIS G3441) | Core Micro-Hardness Bounds | Connection Types Available |
|---|---|---|---|---|
| AISI 4140 Alloy Forged | ISO 10424-1 Group 1 | JIS SCM440 | 285 – 341 HBW | NC38 / NC46 / Regular |
| AISI 4145H Modified Forging | ISO 10424-1 Group 2 | JIS SCM445H | 311 – 341 HBW Full-Body | NC50 / 6-5/8 REG / IF Joints |
| Non-Magnetic Austenitic Alloy | ISO High-Permeability | JIS Custom Non-Mag | ≥ 293 HBW | NC50 / Gas-Tight Premium |
Technical QA/QC Verification
• 100% Traceable API Certification Logs: Every delivery is backed by extensive EN 10204 3.1 Mill Test Certificates (MTC) outlining specific forging reduction ratios, exact Brinell hardness maps, mechanical impact properties, and thread gauge reports. Ready for third-party auditing by SGS, BV, or Intertek.
• Capital Security Guarantee: We remove cross-border transaction risks completely by securing long-term high-volume rotary toolstring supply agreements via 100% Irrevocable Letters of Credit (L/C) at sight terms.
Anti-Rust Packaging & Ocean Logistics
• Fortified Structural Maritime Palletizing: Drill collars are placed on heavy reinforced steel frames or timber supports, strapped with high-tensile metal banding bands, and fitted with robust polymer isolation separators to prevent metal-to-metal rubbing during rough ocean transit.
• Extended Destination Port Demurrage: Our logistics offices coordinate 14 to 21 days of complimentary container or breakbulk demurrage at your discharge terminal to simplify local custom declaration and coordinate domestic haulage.
API SPEC 7-1 drill collar is made with rolling or forging AISI4145H chromium molybdenum alloy steel. Therefore, it needs to control chemical composition and the content of trace elements effectively.
Specification
Drill Pipe Specifications
| Standard | Number | OD (in.) | ID (in.) | Length (ft) | Weight (lb/ft) | Typical Bending Strength Ratio |
|---|---|---|---|---|---|---|
| SY5144-2007/API7-1 | NC 23-31 | 3-1/8 | 1-1/4 | 30 | 22 | 2.57:1 |
| NC 26-35 (2-3/8 IF) | 3-1/2 | 1-1/2 | 30 | 27 | 2.42:1 | |
| NC 31-41 (2-7/8 IF) | 4-1/8 | 2 | 30 or 31 | 34 | 2.43:1 | |
| NC 35-47 | 4-3 /4 | 2 | 30 or 31 | 47 | 2.58:1 | |
| NC 38-50 (3-1/2 IF) | 5 | 2-1/4 | 30 or 31 | 54 | 2.38:1 | |
| NC 44-60 | 6 | 2-1/4 | 30 or 31 | 83 |
Packing and shipping
Our company has passed ISO9001 quality management system certification, Our Mill product with CE/EN10204 / ASTM/Classification society certificate/CASO/BIS etc certificate.All the customers give good appreciation to our products.We are glad to be your good partner.
Application Areas
Steel is widely used in steel structure workshops, bridge frames, main structures of high-rise buildings, and infrastructure construction (such as highways, oil and gas pipelines). Its high strength properties ensure load-bearing stability and seismic performance. In ship manufacturing, steel is used to build hull structures, decks, and internal components. Hot-rolled coils rely on their load-bearing capacity to adapt to harsh environments.
Factory workshop
With a commitment to excellence, innovation, and sustainability, the company has established itself as a trusted partner in the international steel industry.After nearly two decades of relentless endeavour, our client base now spans over 110 countries and regions across Europe, the Middle East, South America, and Southeast Asia.
Free Bottom-Hole Assembly Layout Audit & Weight-On-Bit Allocation Optimization Assessment
Submitting toolstring tool design sheets for oilfield development projects, directional drilling exploration, or complex heavy deep-well installations? Upload your specific configuration depths, required outer diameters, internal drill bore clearances, connection types, or technical Bill of Materials (BOM) layouts below. Our engineering team will run an optimization calculation to reduce downhole vibration risks and protect your drilling string investment.
