ISO Material Classification Explained

When selecting the right insert for your turning operations, it's important to understand the differences in ISO material classifications. Let's take a closer look at the MSC Edge ISO insert range and how the material groups are distinguished. 

Below we have two images, showing CNMG120408 turning inserts which have the same shape and size dimensionally, but you'll notice one has a black top and gold sides. Whereas the second image is all gold. The key difference lies in the coatings that have been applied to the inserts.

The gold on black inserts feature a special coating that helps dissipate head away from the carbide substrate. This coating enhancement is particulaly beneficial when machining steels and cast irons, as it increases tool life and performance in these applications. These inserts are marked with letters "PK" in their part numbers.

The gold on gold coated inserts, on the other hand, are designed specifically for machining stainless steel and super alloy materials. These workpiece materials work-harden during the cutting process due to having increased levels of chromium, nickel or cobalt in it's make up. The specialised coating on the gold on gold inserts helps to protect the heat fro going into the carbide substrate or workpiece itself. More of the heat generated is then transformed into the swarf chip. This improves the insert's ability to maintain a sharp edge when machining stainless steel and super alloys. These inserts are designed with the "MS" in the code. 

For non-ferrous materials, such as aluminium or brass, an uncoated insert is often the best choice. The lack of a coating helps maintain a super-sharp edge, which is crucial for effectively shearing through softer, non-ferrous materials. These uncoated inserts are marked with the letter "N" in their part code number.

In addition to the material-specific inserts, the MSC Edge range also includes a small number of general-prupose inserts that can be used for machining a variety of materials, including P, K, and M types.

Beyond the coating the inserts also feature distinct differences in the carbide substrate with some insert grades being tougher to handle interrupted cutting. While other inserts are harder which are designed to machine harder and more abrasive alloys under smooth cutting conditions. This is denoted in the ISO code by the last two digits, 15 is the hardest grade while 25 is the toughest.

By understanding the ISO material classification system and how it is applied in the MSC Edge insert range, you can ensure you select the right insert for your specific turning application, whether it's steels, stainles steels, super alloys, or non-ferrous materials.

Watch the full video here or for more tips and insights on machining tools and techniques, stay tuned to our blog, instagram or explore MSC Edge’s comprehensive range of turning inserts today!