Project Description
AISI 4161 Steel Round Bar – Chrome Molybdenum Oil & Gas Grade
Executive Summary
AISI 4161 represents a balanced chrome-molybdenum steel composition delivering reliable mechanical properties for downstream oil and gas equipment manufacturing. Unlike higher-grade steels such as 4330V or 4340, AISI 4161 offers cost-effective solutions for applications requiring moderate strength levels (typically 85-95 ksi yield strength) while maintaining good through-hardening characteristics. SHUNFU Metal supplies AISI 4161 in multiple delivery conditions including hot rolled, normalized, normalized + tempered, and quenched + tempered states. Our manufacturing capabilities ensure consistent quality control with sulfur and phosphorus content maintained at ≤ 0.010% for enhanced NACE MR0175 compliance in sour service environments. Primary applications include valve bodies, wellhead components, production equipment, and general oilfield tooling where API 6A material requirements must be met but extreme strength specifications are not mandated.
Critical Standards & Material Equivalents
| Standard | Designation | Industry Application |
|---|---|---|
| AISI/SAE | 4161 | General Engineering Applications |
| UNS | G41610 | Material Identification System |
| DIN | 1.7131 / 42CrMo4 | European Standard |
| JIS | SCM440 | Japanese Industrial Standard |
| EN | 42CrMo4 | European Norm |
| ASTM | A29/A29M | Hot-Worked Carbon & Alloy Steel Bars |
| API | 6A CRA-13 | Wellhead & Christmas Tree Equipment |
| NACE | MR0175/ISO 15156 | Sour Service Applications |
Chemical Composition Analysis
| Element | Standard Range (%) | SHUNFU Enhanced (%) | Function |
|---|---|---|---|
| Carbon (C) | 0.56 – 0.64 | 0.58 – 0.62 | Strength & hardness foundation |
| Manganese (Mn) | 0.75 – 1.10 | 0.80 – 1.05 | Deoxidation & hardenability |
| Phosphorus (P) | ≤ 0.035 | ≤ 0.010 | Controlled for toughness |
| Sulfur (S) | ≤ 0.040 | ≤ 0.010 | NACE compliance requirement |
| Silicon (Si) | 0.15 – 0.35 | 0.20 – 0.30 | Deoxidation agent |
| Chromium (Cr) | 0.70 – 1.10 | 0.85 – 1.05 | Hardenability & corrosion resistance |
| Molybdenum (Mo) | 0.25 – 0.35 | 0.28 – 0.33 | Temper embrittlement resistance |
| Nickel (Ni) | – | ≤ 0.25 | Residual element control |
| Copper (Cu) | – | ≤ 0.25 | Residual element control |
Mechanical Properties by Heat Treatment Condition
Normalized + Tempered Condition (Standard Delivery)
| Property | Value | Test Method | Application Relevance |
|---|---|---|---|
| Tensile Strength | 125-145 ksi (862-1000 MPa) | ASTM A370 | Design stress calculations |
| Yield Strength (0.2% offset) | 85-95 ksi (586-655 MPa) | ASTM A370 | Working stress limitation |
| Elongation (2″ gage length) | 16-22% | ASTM A370 | Ductility assessment |
| Reduction in Area | 45-55% | ASTM A370 | Material toughness |
| Hardness | 28-35 HRC | ASTM E18 | Machinability indicator |
| Impact Toughness (CVN @ 70°F) | 25-40 ft-lbs | ASTM A370 | Fracture resistance |
Quenched + Tempered Condition (Premium Grade)
| Property | Value | Tempering Temperature | Application |
|---|---|---|---|
| Tensile Strength | 140-160 ksi (965-1103 MPa) | 1000°F (538°C) | High-pressure components |
| Yield Strength | 110-125 ksi (758-862 MPa) | 1000°F (538°C) | Critical load applications |
| Elongation | 14-18% | 1000°F (538°C) | Moderate ductility required |
| Hardness | 32-38 HRC | 1000°F (538°C) | Wear resistance applications |
Oil & Gas Industry Applications
Wellhead Equipment
- Christmas tree components
- Valve bodies and bonnets
- Flanged connections
- Pressure-containing parts
Production Equipment
- Manifold blocks
- Flowline components
- Separator internals
- Choke and throttle valves
Downhole Tools
- Tubing head spools
- Casing head components
- Safety valve bodies
- Completion equipment
Drilling Equipment
- BOP stack components
- Drill pipe connections
- Tool joints
- Rotary table bushings
Heat Treatment Specifications
Standard Processing Route
| Process Step | Temperature Range | Time/Rate | Atmosphere |
|---|---|---|---|
| Normalizing | 1650-1700°F (899-927°C) | 1 hr per inch of section | Protective or neutral |
| Air Cooling | To ambient | Still air | – |
| Tempering | 1100-1200°F (593-649°C) | 2 hrs minimum | Air or neutral |
| Final Cooling | To ambient | Air cool | – |
NACE MR0175/ISO 15156 Compliance
| Parameter | NACE Requirement | SHUNFU Standard | Compliance Method |
|---|---|---|---|
| Hardness Limit | ≤ 36 HRC max | 28-35 HRC typical | Heat treatment control |
| Sulfur Content | ≤ 0.010% | ≤ 0.008% typical | Ladle analysis control |
| Phosphorus Content | ≤ 0.010% | ≤ 0.008% typical | Steelmaking practice |
| SSCC Testing | Method A (NACE TM0177) | Full compliance | Third-party validation |
| Documentation | 3.2 certification | Full traceability | Mill test certificates |
Size Range & Dimensional Capabilities
| Product Form | Size Range | Length Range | Tolerance |
|---|---|---|---|
| Round Bars | 0.5″ to 24″ (12.7-609.6mm) | Up to 40 feet (12.2m) | ±0.005″ on diameter |
| Hollow Bars | 2″ to 16″ OD (50.8-406.4mm) | Up to 20 feet (6.1m) | ±0.010″ on wall thickness |
| Flat Bars | 0.25″ to 12″ thick | Up to 20 feet (6.1m) | ±0.010″ on thickness |
| Square Bars | 0.5″ to 12″ square | Up to 20 feet (6.1m) | ±0.005″ on sides |
Machinability & Fabrication Guidelines
Recommended Cutting Parameters
| Operation | Tool Material | Cutting Speed | Feed Rate |
|---|---|---|---|
| Turning | Carbide (TiN coated) | 250-350 SFM | 0.008-0.020 IPR |
| Drilling | HSS or Carbide | 100-200 SFM | 0.005-0.015 IPR |
| Milling | Carbide | 300-450 SFM | 0.003-0.012 IPT |
| Grinding | Aluminum Oxide | 5500-6500 SFPM | Light passes |
Welding Considerations
- Preheating: 400-500°F (204-260°C) minimum
- Interpass Temperature: Maximum 600°F (315°C)
- Post-weld Heat Treatment: Stress relief @ 1150°F (621°C)
- Filler Metal: AWS E11018-M or equivalent low-hydrogen electrode
- Heat Input Control: 30-50 kJ/in maximum to prevent HAZ softening
Ready to Source AISI 4161 Steel for Your Project?
SHUNFU Metal delivers premium quality AISI 4161 steel round bars with full traceability, comprehensive testing, and industry-leading technical support. Our experienced metallurgical team ensures your material specifications are met precisely.
📧 Email: [email protected]
📞 Phone: +86-731-89903933
🏢 Address: No. 811, Building C2, Yongsheng Commercial Plaza, 222 Labor East Road, Yuhua District, Changsha City, Hunan, China
Quality Assurance Program
| Test Type | Frequency | Standard | Acceptance Criteria |
|---|---|---|---|
| Chemical Analysis | Per heat | ASTM E415 | Within specification limits |
| Tensile Testing | Per lot | ASTM A370 | Mechanical property requirements |
| Hardness Survey | Per bar | ASTM E18 | Uniform through-section |
| Ultrasonic Inspection | 100% (if specified) | SEP 1921 Class C/c | No unacceptable reflectors |
| Macro Etch | Per specification | ASTM E381 | Homogeneous structure |
| Dimensional Inspection | Statistical basis | Customer drawings | Within tolerance |
We are committed to integrate steel resources in china and serve the global steel market. Our company has more than 15 years of experience in steel researching, production, managing and sales. And our team mostly are based on and worked in national famous steel enterprise before. In the aspect of resources and information, we have established cooperative relationship with nearly hundred enterprises, either state-owned or private owned in China.
What’s more, we have built long, deep and close business relationship with dozens of steel company, Sharing and holding equities with several steel enterprises. Because of the close cooperation with steel companies and our pioneering spirit, which can ensure us stay at the top competition, and ensure our customers get what they really want. We provide preffesional one-stop service to the Contractors of follows project:
- Oil and Gas Pipeline Construction
- Onshore and Offshore
- Boiler Manufacturers
- Oil Refining Equipment
- Petroleum and Chemical Plant Construction
- Fire Protection
- Heating & Air Conditioning
Our ability to purchase materials directly from leading mills at the best possible price will give you the competitive edge. This coupled with a skilled workforce dedicated to embracing the demands of the markets we serve. Just give us a call +86-731-89903933.
