End milling

When using large diameter end mills it is recommended to use indexable insert or brazed type tools, rather than solid end mills. This is because the raw material costs of large diameter solid end mills are high, therefore making the overall tool price also high. The insert of an indexable insert tool can be changed for a different type that can be used for different workpiece materials and cutting conditions, enabling significant tool consolidation. However, the body of an indexable insert end mill is made from steel and has lower rigidity than a solid carbide end mill with the same diameter. Additionally, the cutting edge accuracy is not as good as solid end mills and the clamping of the insert means that production of small diameter indexable insert end mills are usually restricted to diameters of 10mm and above.

When using small diameter end mills and a good surface finish is required, it is recommended to use solid end mills with high cutting edge accuracy. There are fewer limitations to the cutter paths of solid end mills that have continuous flutes, rather than indexable insert type end mills where the cutting edge is interrupted.

Considering machining accuracy and tool costs; generally, for roughing and semi-finishing medium or large diameter indexable insert end mills are recommended. For applications that require smaller diameters, the use of solid end mills is recommended even for roughing and semi-finishing.

Some indexable insert end mills now have increased insert tolerance and clamping accuracy. Additionally some types now also have carbide shanks. This means that improved surface finishes can be achieved. Conversely, there are also roughing type end mills, so the method of use of an end mill depends entirely on the type of application.