High-Strength Alloy Structural Steel Round Bar – Precision Ground & Heat Treated
Price:
800 - 1200 USD/Ton
MOQ:
1 Ton
Delivery Time:
5 - 12 days based on the quantity
Brand:
DELTA
Product Description
High-Strength Alloy Structural Steel Round Bar – Precision Ground & Heat Treated
Products Specification
|
Products Name |
Alloy Steel Round Bar |
|
Diameter |
20 - 350 mm |
|
Length |
6m or custom cutting any length as request |
|
Type |
Hot Rolled |
|
Brand |
BAOSTEEL DELTA DONGBEI HUAXI SHAGANG.etc |
|
MOQ |
1 Ton |
|
Loading Port |
Shanghai Port |
|
Packing |
packing by steel wire rope |
|
Deliver time |
5 - 7 days for stock materials |
|
Other Grade |
Q195,Q235,10#,20#,35#,45#,Q215,Q345,12Cr1Mov,15CrMo ,20Cr,40Cr,20CrMo,35CrMo,42CrMo,40CrNiMo,GCr15,65Mn,50Mn, 50Cr,3Cr2W8V,20CrMnTi,25Cr2MoVA,5CrMnMo ,38CrMoAl, 30CrMnSiA,B16,31CrMoV9 |
|
Standard |
ASTM GB EN DIN |
|
Application |
Structure and Industrial |
High-Strength Alloy Structural Steel Round Bar – Precision Ground & Heat Treated
Product Overview
Our High-Strength Alloy Structural Steel Round Bar is engineered for demanding industrial applications that require exceptional mechanical properties, dimensional accuracy, and long-term reliability. Manufactured from premium-grade alloy structural steel (conforming to standards such as GB/T 3077, ISO 683-1, and ASTM A322/A434), each bar undergoes precision grinding and controlled heat treatment (typically quenching and tempering) to achieve optimal strength, toughness, and surface finish.
Ideal for use in aerospace components, heavy machinery shafts, hydraulic rods, high-performance automotive parts, oil & gas drilling equipment, and precision tooling, this product delivers consistent performance under extreme stress, fatigue, and wear conditions.
Key Features & Benefits
- ✅ High Yield & Tensile Strength: Achieves yield strengths up to 900–1200 MPa (depending on grade and heat treatment).
- ✅ Precision Ground Surface: Surface roughness as low as Ra 0.4–0.8 µm, ensuring excellent fit and reduced friction in dynamic assemblies.
- ✅ Uniform Hardness & Microstructure: Full through-hardening with minimal distortion due to controlled quenching and tempering cycles.
- ✅ Tight Dimensional Tolerances: Diameter tolerance up to h6/h7 per ISO 286, suitable for direct machining or press-fit applications.
- ✅ Enhanced Fatigue Resistance: Ideal for cyclic loading environments (e.g., crankshafts, connecting rods).
- ✅ Traceable Certification: Mill test reports (MTRs) provided per EN 10204 3.1, including chemical composition and mechanical test data.
Common Grades & Specifications
| Grade (GB/T 3077) | Equivalent (AISI/SAE) | Chemical Composition (Typical %) | Typical Applications |
|---|---|---|---|
| 40Cr | 5140 | C: 0.37–0.44, Cr: 0.80–1.10 | Gears, axles, bolts |
| 42CrMo4 | 4140 | C: 0.38–0.45, Cr: 0.90–1.20, Mo: 0.15–0.25 | High-stress shafts, drill collars |
| 35CrMo | 4135 | C: 0.32–0.40, Cr: 0.80–1.10, Mo: 0.15–0.25 | Turbine rotors, fasteners |
| 20CrMnTi | 8620 | C: 0.17–0.23, Cr: 1.00–1.30, Mn: 0.80–1.10, Ti: 0.04–0.10 | Case-hardened gears |
| 38CrMoAl | — | C: 0.35–0.42, Cr: 1.35–1.65, Mo: 0.08–0.15, Al: 0.70–1.10 | Nitriding shafts, wear-resistant parts |
Mechanical Properties After Heat Treatment (Quenched & Tempered)
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) | Impact Toughness (J @ -20°C) |
|---|---|---|---|---|---|
| 40Cr | 980–1100 | ≥785 | ≥9 | 285–341 | ≥47 |
| 42CrMo4 | 1080–1250 | ≥930 | ≥10 | 302–363 | ≥54 |
| 35CrMo | 930–1080 | ≥785 | ≥10 | 269–321 | ≥63 |
| 38CrMoAl | 930–1030 | ≥785 | ≥12 | 229–285 | ≥78 |
Properties may vary slightly based on bar diameter and exact heat treatment parameters.
Manufacturing Process
- Melting & Casting: Electric arc furnace (EAF) + LF refining + VD degassing for ultra-clean steel.
- Hot Rolling: Continuous rolling to near-net shape with controlled cooling.
- Straightening & Stress Relieving: To minimize residual stresses.
- Precision Grinding: Centerless or between-centers grinding to achieve h6/h7 tolerances and smooth surface.
- Heat Treatment:
- Austenitizing at 840–880°C (grade-dependent)
- Oil or polymer quenching
- Tempering at 500–650°C for desired strength-toughness balance
- Final Inspection: Ultrasonic testing (optional), hardness verification, dimensional check, and visual inspection.
Dimensional Range & Availability
| Parameter | Range |
|---|---|
| Diameter | 10 mm – 300 mm |
| Length | 2,000 mm – 6,000 mm (custom lengths available) |
| Surface Finish | Ground (Ra ≤ 0.8 µm), optional polished |
| Tolerance (Diameter) | h6 (±0.007 mm for Ø20 mm), h7 standard |
| Straightness | ≤0.2 mm/m |
| Packaging | Bundled with anti-rust oil, wooden pallets, seaworthy export packing |
Why Choose Our Precision-Ground High-Strength Alloy Steel Bars?
- Consistency: Batch-to-batch uniformity ensured by integrated production control from melt to finish.
- Certification: Full compliance with ISO 9001, IATF 16949 (for automotive), and material traceability via heat number.
- Customization: We offer tailored heat treatment profiles (e.g., higher toughness for cryogenic use or elevated hardness for wear resistance).
- Global Delivery: Ready stock for common sizes; lead time 15–30 days for custom orders.
- Technical Support: Our metallurgical engineers assist with grade selection, processing advice, and failure analysis.
Applications Across Industries
- Automotive: Camshafts, steering knuckles, suspension components
- Aerospace: Landing gear pins, actuator rods
- Energy: Downhole tools, pump shafts, turbine spindles
- Construction Machinery: Excavator pins, hydraulic cylinders
- Industrial Equipment: High-load rollers, spindle bars, coupling hubs
Quality Assurance & Testing
Every batch undergoes rigorous quality checks:
- Chemical Analysis: Spectrometry (OES) for precise elemental control
- Tensile Testing: Per GB/T 228.1 or ASTM E8
- Charpy Impact Test: At room and sub-zero temperatures
- Hardness Mapping: Cross-section verification
- Non-Destructive Testing (NDT): Optional ultrasonic (UT) or magnetic particle inspection (MPI) for critical applications
Ordering Information
When placing an order, please specify:
- Steel grade (e.g., 42CrMo4 / AISI 4140)
- Diameter and length
- Required tolerance class (h6, h7, etc.)
- Heat treatment condition (Q+T, normalized, etc.)
- Surface finish requirement
- Quantity and delivery terms (FOB, CIF, etc.)
Sample pieces available upon request for prototyping and validation.
Sustainability & Compliance
Our production adheres to environmental regulations (ISO 14001) and uses recycled scrap as primary raw material. All products are RoHS and REACH compliant, with full documentation available.
Conclusion
The High-Strength Alloy Structural Steel Round Bar – Precision Ground & Heat Treated represents the pinnacle of engineered bar stock for high-performance engineering. By combining advanced metallurgy, precision finishing, and stringent quality control, we deliver a product that reduces machining time, enhances component life, and ensures reliability in the most challenging environments.
Similar Products
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.
Company
JIANGSU MITTEL STEEL INDUSTRIAL LIMITED
Location
No.283-1, Youyi Middle Road, Xishan District, Wuxi City, Jiangsu Province
Contact Person
Gao Ben