Cold Rolled Head and Tail Not Cold Portion Length Specification Overview
Cold rolling is the most commonly used method for creating steel products. In this process, the metal is cooled and then rolled, which both increases its strength and creates better shape. It also gives steel a much smoother finish. Cold rolling is often used to create thin strips and other small steel components, such as automotive and appliance parts. While cold rolling can provide many benefits, it does come with some unique considerations. One such consideration is the length of the steel product’s “cold” section at its head and tail, which should not be rolled cold, as doing so could increase the risk of cracking.
In cold rolling applications, steel products are typically placed in a cooling environment directly before they are rolled. This cooling environment helps to ensure that the steel remains at a cool temperature while it is being rolled, which reduces the risk of cracking. While the cold rolling process should not start until the steel product has sufficiently cooled in the cooling environment, it is also important to note that the last few inches of the head and tail of the product should not be rolled cold. This is because these portions of the steel product are known as the “not-cold” portions, and their length is often specified for each steel product.
There are a few factors that can influence the length of not-cold steel sections. The first is the thickness of the steel product. Generally, thicker steel products need longer not-cold sections, as thicker steel requires more energy to be rolled cold and is therefore more likely to crack when it is rolled cold. In addition, the hardness of the steel product can also influence the length of the not-cold portion. As a rule of thumb, the harder the steel, the shorter the not-cold section should be.
When it comes to specifying not-cold portions of steel products, many manufacturers use the American Society for Testing and Materials (ASTM) guidelines. Different types of steel products have their own specific ASTM recommendations for not-cold portion length. For instance, for cold-rolled steel products that are up to 0.125 inches thick, the not-cold portion should not exceed 0.062 inches. For steel products with thicker sections, the not-cold portion should be longer. For instance, for steel products that are 0.125 inches to 0.5 inches thick, the not-cold portion should not exceed 0.125 inches.
In conclusion, when it comes to cold-rolled steel products, the not-cold portion of the head and tail section should not be rolled cold. The length of the not-cold portion should be specified according to the type and thickness of the steel product, with thicker steel products requiring longer not-cold sections. The ASTM guidelines should be used when determining the lengths of the not-cold sections.
