There are a few important differences between hot rolled and cold rolled steel. First, the main difference relates to the way the metals are processed at the mill. Hot rolled steel involves roll pressing at very high temperatures. And cold rolled steel involves further processing at a cold rolling mill.
Hot rolled steel has been roll pressed at high temperatures – above the re-crystallization temperature – over 1,700˚F. As a result, the steel can be shaped and formed easily.
The mill first starts with a large rectangular length of metal called a billet. The billet is heated and then flattened into a large roll. Next, at a constant high temperature, it passes through a series of rollers to achieve its finished dimensions.
Hot rolled steel is less expensive than cold rolled steel, because it goes through less processing. Hot rolled steel shrinks slightly when it cools off. As a result, the finished product has looser size tolerances compared to cold rolled.
Hot rolled steel characteristics:
- A scaled surface
- Looser size tolerances
- Less hardness
Cold rolled steel is hot rolled steel that goes through further processing. Cold reduction mills process the steel. The process consists of rolling the steel at room temperature. As a result, its strength and hardness increases.
In addition, cold rolling produces closer size tolerances and better finishes compared to hot rolled steel.
Cold rolled steel characteristics:
- Better finished surface
- Closer size tolerances
- Higher strength and hardness
It is best to go with a proven expert in their field. Call us if your company requires a secure supply of stainless, aluminum, cold-rolled or galvanized sheet metal.
We can help you with any stocking requirement level. From a few skids to hundreds of tons. We will help you schedule out the material you need to meet production without shortages.
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