Hot Rolled Flat Bars
About Hot Rolled Flat Bars
Hot rolled steel flat bar is a structural A36 steel with 36,000 PSI minimum yield strength and excellent weldability. Conforms to ASTM A36. Ideal for frames, supports, and general fabrication.
Quick Facts
- Material: A36 Hot Rolled Steel
- ASTM Standard: A36
- Available Sizes: Widths from 1/2", Thicknesses from 1/8"
- Location: Los Angeles warehouse
- Services: Custom size, same-day pickup
Overview
Hot rolled (HR) flat bar is formed at elevated temperatures, resulting in a product with a distinctive scaly, blue-grey finish and slightly rounded edges. This process makes it more malleable and cost-effective than cold rolled steel. The material's less precise tolerances are suitable for applications where surface finish and exact dimensions are not the primary concern, such as structural components and heavy equipment fabrication.
Primarily produced to ASTM A36 specifications, this steel offers a minimum yield strength of 36,000 PSI, ensuring reliable performance in structural roles. Its carbon content provides excellent weldability using common methods like MIG and stick welding. It is also easily drilled, punched, and formed, making it a versatile choice for brackets, base plates, braces, and ornamental ironwork where strength is a key requirement.
Technical Specifications
Mechanical Properties
| Property | Value | Unit |
|---|---|---|
| Tensile Strength | 58,000-80,000 | PSI |
| Yield Strength | 36,000 | PSI |
| Elongation | 20 | % |
| Hardness | 119-162 | HB |
Chemical Composition (Typical for A36)
| Element | Percentage |
|---|---|
| Carbon (C) | ⤠0.26% |
| Manganese (Mn) | 0.80% - 1.20% |
| Phosphorus (P) | ⤠0.04% |
| Sulfur (S) | ⤠0.05% |
| Silicon (Si) | ⤠0.40% |
| Copper (Cu) | âĨ 0.20% (when specified) |
Applicable Standards
- ASTM A36: Standard Specification for Carbon Structural Steel
Common Applications
- Structural Framing: Brackets, gussets, and support braces - Excellent strength-to-weight ratio and weldability.
- General Fabrication: Base plates for columns and machinery - Good compressive strength and easy to drill.
- Industrial Maintenance: Repair patches and reinforcement sections - Cost-effective and readily available.
- Transportation: Trailer frames and chassis components - High durability and resistance to deformation.
- Agricultural Equipment: Implement hitches, frames, and supports - Withstands rough use and is easy to repair.
- Architectural & Ornamental: Gate frames, fence posts, and decorative ironwork - Formable and strong for custom designs.
- Construction: Concrete forms, shims, and temporary supports - Low cost and versatile for job site needs.
- Machinery: Levers, linkages, and mounting plates - Provides a solid foundation for moving parts.
Working with Hot Rolled Flat Bars
Machining
A36 steel has fair machinability. It produces gummy chips, so slower speeds, high feed rates, and a good cutting fluid are recommended for best results. Its softness can cause tool wear, but it is readily drilled, tapped, and milled with standard high-speed steel tooling.
Welding
A36 steel is one of the easiest steels to weld. It has excellent weldability and is compatible with all standard welding processes, including MIG (GMAW), stick (SMAW), and TIG (GTAW), without requiring pre-heating or post-heating for most sections. Common filler metals are E7018 and ER70S-6.
Finishing
The hot rolled surface has a mill scale that must be removed by grinding, sandblasting, or pickling before painting, powder coating, or galvanizing. Left unfinished, it will rust. Oiling can provide temporary corrosion resistance for storage.
Related Products
Frequently Asked Questions
Q: What's the difference between hot rolled and cold rolled flat bar?
A: Hot rolled flat bar is formed at high temperature, giving it a rougher, scaled surface and looser tolerances. Cold rolled is processed at room temperature for a smoother finish, sharper corners, and more precise dimensions, but is more expensive.
Q: Can A36 flat bar be hardened?
A: A36 is a low-carbon steel and does not respond well to through-hardening heat treatments. However, it can be case-hardened through processes like carburizing to create a hard, wear-resistant surface while maintaining a ductile core.
Q: Is A36 steel magnetic?
A: Yes, as a carbon steel, A36 is ferromagnetic and is strongly attracted to magnets.
Stock & Custom Sizes
Available widths: 1/2" to 12". Thicknesses: 1/8" to 2". Standard lengths: 12 ft. Custom size available.
Same-day cutting and Los Angeles pickup available.
View Sizes & PricingNeed Hot Rolled Flat Bars? Contact Bobco Metals for availability and Los Angeles pickup.
Request a Quote Ask an Expert