Overview
Hot rolled steel sheet is produced by passing steel through rollers at temperatures above its recrystallization point, typically over 1,700°F. This high-temperature process makes the steel easy to form and shape. The material develops a characteristic dark, scaly surface finish, known as mill scale, as it cools. This process results in a product with looser dimensional tolerances compared to cold rolled steel, making it a cost-effective choice for applications where precise dimensions and a smooth finish are not primary requirements.
The primary advantage of A36 hot rolled sheet is its combination of strength, ductility, and weldability. Its minimum yield strength of 36,000 PSI is suitable for a wide range of structural applications. The material's ductility allows it to be bent and formed without fracturing, while its chemical composition ensures it can be easily welded using all common techniques. These properties make it a versatile and reliable material for construction, equipment manufacturing, and industrial maintenance and repair projects.
Technical Specifications
â ī¸ Reference Data Only: Values shown are typical industry standards and may vary by manufacturer, lot, and heat treatment. For critical applications, please contact us to verify specifications or request a Mill Test Report (MTR).
Mechanical Properties
| Property |
Value |
Unit |
| Tensile Strength | 58,000 - 80,000 | PSI |
| Yield Strength | 36,000 | PSI |
| Elongation | 20 | % |
| Hardness | 119-162 | HB |
Applicable Standards
- ASTM A36: Standard Specification for Carbon Structural Steel
Working with Hot Rolled Sheets
Machining
Hot rolled A36 steel has fair machinability. The tough, abrasive mill scale on the surface can increase tool wear. It is recommended to use slower cutting speeds and heavier feeds to get beneath the scale. Using a cutting fluid will improve tool life and surface finish.
Welding
A36 steel has excellent weldability and is compatible with all standard welding processes, including MIG (GMAW), Stick (SMAW), and TIG (GTAW). Preheating is generally not required for the thicknesses found in sheet material. The mill scale should be removed from the weld area for the strongest, cleanest weld.
Finishing
The mill scale surface must be removed before painting, powder coating, or plating to ensure proper adhesion. Common methods for surface preparation include grinding, sandblasting, or acid pickling. The material can also be hot-dip galvanized for superior corrosion resistance.
Frequently Asked Questions
Q: What is the difference between hot rolled and cold rolled steel sheet?
A: Hot rolled sheet is processed at high temperatures, resulting in a rough, scaly surface and looser tolerances. Cold rolled sheet is processed at room temperature, which produces a smooth, oil-finished surface with tighter, more precise dimensions and a slightly higher strength.
Q: Do I need to remove the mill scale before welding?
A: For the highest quality and strongest welds, it is highly recommended to remove the mill scale from the joint area by grinding or wire brushing. While it is possible to weld through light scale, it can introduce impurities into the weld pool.
Q: Is A36 steel sheet magnetic?
A: Yes, as a carbon steel, A36 is a ferrous material and is magnetic. This property is useful for applications involving magnetic handling or fixturing during fabrication.
