45# Carbon Steel Bar - Hot Rolled & Cold Drawn ASTM A29 Grade

45# carbon steel bar is a medium-carbon structural steel material extensively employed in manufacturing applications requiring superior mechanical strength and machinability. With a carbon content of 0.42-0.50%, this grade delivers excellent tensile properties of 600 MPa minimum, making it the preferred choice for machinery components, automotive parts, and industrial tooling. Our mill-direct 45# carbon steel bar serves manufacturers, fabricators, and engineering firms seeking cost-effective solutions for high-stress applications.

What is 45# Carbon Steel Bar?

45# carbon steel bar is a medium-carbon alloy conforming to GB/T 699-2015 standards, characterized by a balanced composition of 0.42-0.50% carbon, 0.50-0.80% manganese, and controlled silicon content. This material finds extensive application in manufacturing crankshafts, gears, connecting rods, and structural components where moderate hardness combined with good toughness is essential.

45# Carbon Steel Bar Technical Specifications

Our 45# carbon steel bar complies with GB/T 699-2015 Section 5.2 for chemical composition and ASTM A29/A29M-20 for dimensional tolerances. Key properties include tensile strength of 600 MPa minimum, yield strength of 355 MPa, and elongation of 16% minimum in the hot-rolled condition. Available in round bar diameters from 10mm to 300mm with straightness tolerance of 2mm per meter length.

Manufacturing Process & Quality Control

We produce 45# carbon steel bar through controlled hot rolling at temperatures between 1150-1200°C, followed by air cooling or normalized heat treatment depending on application requirements. Cold-drawn variants undergo additional processing to achieve superior surface finish of Ra 1.6μm and tighter diameter tolerances of ±0.05mm. Each production lot undergoes spectroscopic analysis and mechanical testing per ISO 6892-1:2019 standards.

Applications & Industry Use Cases

This medium-carbon steel grade serves critical roles in automotive manufacturing for transmission shafts and suspension components, industrial machinery for hydraulic cylinders and pump shafts, and agricultural equipment for plow blades and tiller components. The material's exceptional response to heat treatment enables surface hardening to 55-60 HRC while maintaining a tough core, ideal for wear-resistant applications.

Frequently Asked Questions

What is the minimum order quantity (MOQ)?

Our standard MOQ for 45# carbon steel bar is 5 metric tons per specification. For specialized sizes or heat treatment requirements, we accommodate orders starting from 10 tons to ensure production efficiency. Mixed container loads are available for distributors requiring multiple diameter ranges.

Do you provide material test certificates?

Yes, we supply EN 10204 Type 3.1 mill test certificates with every shipment, documenting chemical composition per GB/T 699-2015, mechanical properties including tensile strength and impact values, and heat treatment records. Third-party inspection by SGS, BV, or TÜV can be arranged upon request.

What is the typical delivery time?

Standard diameter 45# carbon steel bar (20-100mm) ships within 15-20 days from order confirmation for stock sizes. Custom diameters or heat-treated variants require 25-35 days production lead time. Express processing is available for urgent requirements with 10-day delivery for premium charges.

Can you cut to custom sizes?

We provide precision cutting services with tolerance of ±1mm for lengths up to 6 meters. Our sawing facility handles both straight cuts and beveled ends at angles from 30° to 90°. Volume orders benefit from free cutting services when total quantity exceeds 20 tons per specification.

Get a Competitive Quote for 45# Carbon Steel Bar

Request factory-competitive pricing for your 45# carbon steel bar requirements today. Our technical sales team provides detailed quotations within 24 hours, including material specifications, processing options, and logistics solutions. Contact us for volume discounts on orders exceeding 50 tons or long-term supply agreements with locked-in pricing for 6-12 month periods.