Hot-rolled Alloy Steel Bars – ASTM A615/A706, Custom Sizes & Grades

Shandong Kuaima Steel Co., Ltd.

Verified Custom manufacturer 7yrs

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Technical Specifications of Hot-Rolled Alloy Steel Bars

Property	Parameter	Description
Product Name	Hot-Rolled Alloy Steel Bars	High-strength steel bars produced through hot rolling process
Material Grade	AISI 4140 / 42CrMo4 / SCM440 / GB 42CrMo	International grade equivalents for alloy steel
Standard Compliance	ASTM A322, EN 10083-3, JIS G4105, GB/T 3077	Meets major international standards
Carbon (C)	0.38-0.43%	Carbon content for optimal strength
Chromium (Cr)	0.80-1.10%	Enhances hardenability and wear resistance
Molybdenum (Mo)	0.15-0.25%	Improves toughness and high-temperature strength
Manganese (Mn)	0.75-1.00%	Improves hardenability and tensile strength
Silicon (Si)	0.15-0.35%	Deoxidizer and strengthener
Tensile Strength	≥655 MPa	Minimum tensile strength per ASTM A322
Yield Strength	≥415 MPa	Minimum yield strength
Elongation	≥16%	Ductility in 50mm gauge length
Hardness	197-255 HBW	Brinell hardness range for annealed condition
Diameter Range	10mm - 350mm	Available diameter options for round bars
Length	3m - 12m or custom	Standard and custom lengths available
Surface Finish	Black, Peeled, Polished, Machined	Multiple surface treatment options
Heat Treatment	Annealed, Normalized, Quenched & Tempered	Various heat treatment conditions available
Application	Machinery parts, gears, shafts, automotive components	Typical industrial applications
Certification	EN 10204 3.1, ISO 9001, ASTM certification	Quality certifications provided
Packaging	Bundled with steel straps, waterproof wrapping	Standard export packaging
MOQ	5 tons	Minimum order quantity

Hot-rolled Alloy Steel Bars – ASTM A615/A706, Custom Sizes & Grades

Hot-rolled alloy steel bars represent a fundamental category of long steel products engineered for applications demanding superior mechanical strength and enhanced material properties. Manufactured through controlled hot rolling processes at temperatures exceeding 1700°F (927°C), these bars incorporate precise alloying elements to achieve specific performance characteristics. Industries ranging from construction and automotive to energy generation rely on these materials for critical structural components, reinforcement systems, and precision-machined parts where standard carbon steel proves insufficient.

Hot-rolled alloy steel bars supplier

What is Hot-rolled Alloy Steel Bars?

Hot-rolled alloy steel bars are semi-finished steel products produced by passing heated steel billets through a series of rolling mills to achieve desired cross-sectional shapes and dimensions. The alloying process introduces elements such as chromium, molybdenum, nickel, and vanadium in controlled percentages, resulting in enhanced hardenability, wear resistance, and elevated temperature performance compared to conventional carbon steel bars.

Hot-rolled Alloy Steel Bars Technical Specifications

Our hot-rolled alloy steel bars comply with ASTM A615/A615M-20 for deformed and plain billet-steel bars and ASTM A706/A706M-16 for low-alloy steel deformed and plain bars. Standard grades include 4140 (chromium-molybdenum alloy with 0.80-1.10% Cr and 0.15-0.25% Mo), 4340 (nickel-chromium-molybdenum alloy offering 1.65-2.00% Ni), and 8620 (nickel-chromium-molybdenum carburizing grade). Available diameters range from 0.375 inches to 12 inches with length options up to 40 feet, manufactured to meet ASTM E45 inclusion rating requirements.

Hot-rolled alloy steel bars manufacturer

Why Choose Our Hot-rolled Alloy Steel Bars

We maintain ISO 9001:2015 certified production facilities equipped with advanced continuous casting technology and precision rolling mills capable of holding dimensional tolerances within ±0.005 inches. Each production lot undergoes spectrographic analysis per ASTM E415 and tensile testing according to ASTM A370, with full material traceability and mill test certificates provided. Our direct mill relationships enable competitive factory pricing while maintaining consistent chemical composition control and mechanical property verification for demanding engineering applications.

Frequently Asked Questions

What is the minimum order quantity (MOQ)?

Our standard minimum order quantity stands at 5 metric tons per specification. For specialty grades or non-standard dimensions, we accommodate orders starting at 10 metric tons. Mixed-grade orders meeting the 5-ton threshold are accepted with prior production scheduling coordination.

Do you provide material test certificates?

Yes, we supply EN 10204 Type 3.1 mill test certificates with every shipment, documenting chemical composition analysis, mechanical property test results, heat treatment records, and dimensional inspection data. Certificates include heat number traceability and are signed by both the manufacturer's authorized representative and an independent inspection body.

What is the typical delivery time?

Standard grade hot-rolled alloy steel bars in common sizes ship within 4-6 weeks from order confirmation. Custom specifications requiring special rolling or heat treatment extend lead times to 8-12 weeks. Expedited production is available for critical projects with supplementary scheduling fees.

Can you cut to custom sizes?

We offer precision cutting services utilizing bandsaw and abrasive cutting methods to achieve length tolerances of +0/-0.125 inches. Custom length cutting is available for bars up to 40 feet with minimum piece lengths of 6 inches. Additional machining services including turning, milling, and centerless grinding can be arranged through our affiliated processing partners.

Get a Competitive Quote for Hot-rolled Alloy Steel Bars

Request your detailed quotation today by providing material grade specifications, required dimensions, quantity, and delivery location. Our technical sales team responds within 24 hours with mill-direct pricing, availability confirmation, and application engineering support. Contact us to discuss your specific alloy steel bar requirements and benefit from our extensive inventory of ASTM-certified materials ready for immediate processing and shipment.

Hot-rolled alloy steel bars China

Ratings & Reviews

5.0

Very satisfied

Based on 8 reviews for verified purchases

Supplier service

5.0

On-time shipment

5.0

Supplier service

5.0

William Taylor

Australia

verified purchases

2025-09-11

Acceptable Quality with Initial Documentation Issues
Purchased 7 tons of 4140 bars (40mm diameter, 12-foot lengths) for marine winch components. Material quality was acceptable with chemistry meeting ASTM specifications. Initial mill certificates had incorrect heat numbers that required correction and reissue, causing 5-day delay in our production schedule. Supplier resolved the documentation error promptly and provided verified certificates with proper traceability. Mechanical properties tested satisfactorily at our facility. Would recommend improving quality control on paperwork before shipment.

Ahmed Al-Hassan

UAE

verified purchases

2025-09-28

Superior ASTM A615 Deformed Bars with Complete Documentation
Ordered 20 tons of ASTM A615 Grade 75 deformed bars (16mm, 20mm, 25mm diameters) for high-rise building foundations. Mill certificates included complete chemical analysis showing 0.48% carbon, mechanical test results with 520 MPa yield, and dimensional inspection data. Rib height and spacing conformed to ASTM requirements. Supplier coordinated mixed-diameter shipment efficiently. Delivered in 35 days to Dubai with proper export documentation. Material passed our third-party inspection without issues.

Carlos Silva

Brazil

verified purchases

2025-10-15

Perfect Custom-Cut 4140 Bars for Mining Equipment
This is our fourth order for 4140 alloy bars. Latest shipment was 9 tons cut to custom 1.2-meter lengths for crusher shaft production. Supplier's precision cutting service achieved length tolerance of +0/-0.080 inches using bandsaw method. Each piece was individually marked with heat number. Tensile testing per ASTM A370 showed 655 MPa yield strength. Material arrived in 42 days including custom processing. Their consistent quality control and traceability system makes reordering straightforward.

Robert Brown

United Kingdom

verified purchases

2025-11-02

Reliable 4340 Alloy for Aerospace Tooling
Purchased 6 metric tons of 4340 nickel-chromium-molybdenum bars (75mm diameter) for fixture manufacturing. Material hardness tested at 28 HRC in annealed condition. Inclusion rating per ASTM E45 was acceptable at thin series maximum 1.5. Lead time was 10 weeks as quoted. Surface had minor mill scale in two bars that required additional grinding, but mechanical properties were consistent throughout the lot. Pricing was fair for the specification grade.

Wei Chen

Singapore

verified purchases

2025-11-20

Premium Quality ASTM A706 Bars for Seismic Applications
Sourced 15 tons of ASTM A706 Grade 60 deformed bars (20mm and 32mm diameters) for earthquake-resistant construction project. Material certificates documented yield strength at 455 MPa and tensile-to-yield ratio of 1.32, fully compliant with seismic codes. Rib pattern geometry met spacing requirements for concrete bonding. Supplier provided cut-to-length service at 9-meter pieces with +0/-0.100 inch tolerance. Packaging was excellent with proper bundling and moisture protection.

Hans Mueller

Germany

verified purchases

2025-12-08

Good Value 8620 Carburizing Grade for Automotive Parts
Ordered 10 tons of 8620 nickel-chromium-molybdenum bars (35mm diameter) for gear manufacturing. Pricing was competitive compared to three European suppliers we evaluated. Chemical composition met ASTM specifications with 0.52% Ni content verified. Delivery took 9 weeks instead of quoted 8 weeks due to customs documentation delay, but supplier proactively communicated. Material machined well with consistent hardness distribution. Would order again for production runs.

James Wilson

United Kingdom

verified purchases

2025-12-23

Outstanding 4140 Alloy Bars with Fast Technical Support
Purchased 12 metric tons of 4140 chromium-molybdenum bars (50mm diameter, 6-meter lengths) for heavy machinery components. Sales team responded within 18 hours with complete technical specifications and hardness data. Material arrived with spectrographic analysis per ASTM E415 showing 0.95% Cr and 0.21% Mo. Surface finish was smooth with no visible scale. Their engineering support helped us select proper heat treatment parameters. Third order this year.

Michael Torres

United States

verified purchases

2026-01-07

Excellent ASTM A615 Grade 60 Bars for Bridge Reinforcement
Ordered 8 tons of 25mm diameter hot-rolled alloy steel bars conforming to ASTM A615 Grade 60 for our highway bridge project. Chemical composition analysis showed 0.42% carbon and tensile strength tested at 625 MPa, exceeding specification requirements. Mill test certificates were EN 10204 3.1 certified with complete heat traceability. Delivered in 38 days with dimensional tolerances within ±0.003 inches. Material performed exceptionally during our concrete embedment tests.