Hot Rolled Sheet Metal Thickness Tolerance

Hot rolled steel properties.

Hot rolled sheet metal thickness tolerance.

Standard tolerances for cold rolled steel usually choosing material thickness is one of the first steps a designer takes when starting a project. This keeps the market price of hot rolled steel lower. Hot rolled steel starts as a large rectangular length of metal called a billet. Hot rolled mild steel seems to have a wider tolerance for amount of included carbon than does cold rolled steel and is therefore more difficult for a blacksmith to use.

Gague are used to specify the thickness of a metal sheet. Sheet metal is manufactured and delivered from the processing mill rolled to the standard thickness that you specify which is now metric. However this cannot be said about cold rolled sheet and hot rolled sheet. We work with nominal thicknesses so it s important to know the thickness tolerance on the material you chose in order to know if the final product will be suitable for your application.

With these two products the cold rolled product has low carbon content and it is typically annealed making it softer than hot rolled sheet. The billet is first heated and then pre processed where it is. The tolerances in the table and attachments reflect current manufacturing practices and commercial standards and are not representative of the manufacturer s standard gauge which has no inherent tolerances. Dimensional tolerances are usually 2 to 5 of the overall dimension.

During the rolling process the rollers bow slightly which results in the sheets being thinner on the edges. The sheet metal does however have a tolerance on the rolling thickness which needs to be taken into account when designing a tight fitting assembly especially as the sheet metal material gets thicker. Continuous rolling gives the desired final shape a metal sheet 3 mm and upwards or profile. Some metal forming processes allow for more precision than others.

Also for similar metals hot rolled products seem to be less costly than cold rolled ones. The steel cools. An example of this can be found with hot rolled and cold rolled metal. As it is easy to form metal in high temperatures without any extra delays it is possible to produce it in larger quantities than cold rolled steel.

Conversion data chart standard gauges chart gauge tolerance chart useful data page.