Material Specifications & International Equivalents

As a specialized chromium-alloy steel grade within the ASTM system, 5140 seamless tubes maintain precise correspondence with international standards including:

  • China: 40Cr alloy structural steel (GB/T 3077)

  • Germany: 41Cr4 (DIN standards)

  • Japan: SCr440 (JIS G4053)

  • Europe: X42Cr13 (EN standards)

The designation "51" represents chromium-alloy series, while "40" corresponds to approximately 0.40% carbon content, clearly defining its medium-carbon chromium alloy characteristics for mechanical manufacturing applications requiring superior performance to carbon steels.

Mechanical Properties & Performance Characteristics

These heat-treatable alloy tubes demonstrate excellent mechanical capabilities in annealed condition with tensile strength ≥650MPa, yield strength ≥400MPa, and elongation ≥12% . Through proper quenching and tempering processes, the mechanical properties can be significantly enhanced to achieve tensile strength of 800-1000MPa and hardness reaching HRC30-40 , substantially outperforming carbon steels in both strength and fatigue resistance.

The enhanced processing characteristics include superior hardenability compared to carbon steels, enabling more effective through-hardening for larger cross-sectional components. Medium machinability improves significantly after annealing, while welding requires preheating to 200-300°C with controlled cooling to prevent chromium-related cracking . The optimized material response to heat treatment enables customized performance enhancement for specific application requirements.

Technical Advantages:

  • Exceptional wear resistance and fatigue strength

  • Improved impact toughness for heavy-load applications

  • Reliable performance under alternating loads and friction conditions

  • Extended service life in demanding operational environments

  • Balanced mechanical properties through heat treatment optimization

Applications & Industrial Solutions

5140 alloy seamless tubes serve critical applications across multiple heavy-duty sectors:

Mechanical Manufacturing

  • Transmission shafts and gear shafts

  • Connecting rods and crankshafts

  • High-strength fasteners (bolts, nuts)

  • Mold blanks and measuring instrument bases

  • Machine tool spindles

Automotive Industry

  • Transmission gears and axle shafts

  • Steering knuckles and suspension system components

  • Automotive drivetrain parts withstanding high loads and vibration

  • Brake system heavy-duty components

Hydraulic Equipment

  • High-pressure hydraulic cylinders and piston rods

  • Heavy-duty hydraulic pipelines and valve cores

  • High-pressure fluid system components enduring repeated impact

Engineering Machinery

  • Hydraulic supports for excavators and cranes

  • Transmission structural components and track pins

  • Heavy equipment parts requiring wear and deformation resistance

General Heavy-Duty Applications

  • Mining machinery components and agricultural machinery heavy-duty parts

  • Import equipment localization (replacing 40Cr, 41Cr4 material components)

  • Industrial applications demanding reliability and durability

Customization & Delivery Options

5140 tubes are typically supplied in annealed condition (GBK/+A) to facilitate subsequent machining and welding operations. The recommended delivery condition is quenched & tempered (Q&T) providing pre-enhanced high-strength properties that reduce customer heat treatment requirements and associated costs. Precision applications can be served with stress-relieved condition (BKS/+SR) to ensure dimensional stability during precision machining. Tenjan's manufacturing flexibility enables customized solutions in dimensions, surface quality, and mechanical properties to meet specific heavy-duty application requirements.

Tenjan Advantage & Quality Commitment

Supported by 21 years of specialized experience in alloy steel tube manufacturing and comprehensive production capabilities, Tenjan delivers reliable 5140 tubular solutions through advanced quality management systems and technical expertise. Our custom alloy steel capability enables production of various domestic and international alloy steel grades tailored to your specific application requirements. With full-process manufacturing control and professional technical support, we ensure consistent material quality and performance reliability for your most demanding heavy-duty applications. Our flexible order quantities and responsive customer service guarantee seamless project integration and ongoing technical support throughout your operation lifecycle, maintaining our commitment to delivering high-performance alloy solutions that exceed customer expectations for strength, durability, and reliability in challenging operational environments.