Carbide inserts are designed in many different shapes/sizes to work their best in a variety of materials while machining, based on their insert strength. The basic shapes listed from strongest to weakest are
As you can see the inserts which have a rather smaller angle are weaker, and the inserts with wider angle have more strength.
The size of the cross section between the cutting edge and the opposite side of the insert determines the difference in insert strength.
Knowing basic insert shapes and which are the strongest and weakest in each application can help you choose the right insert for your application.
for straight heavy roughing, choose a round or square insert, rather than the 35-degree diamond shape.
For a finishing profile application, choose a 35-degree diamond insert, rather than a round or square insert (see illustrations).
In both applications, the shape of the insert best suits the application.