What’s the difference between End Mills Helix angle 35° and 45°

The greater the helix angle of the end mill, the longer the contact length between the work piece and the cutting edge. This can reduce the load per unit length of the cutting edge, so the tool life can be extended. But at the same time, the cutting resistance will increase, so you must consider using a tool holder with high clamping rigidity.

How to choose the right helix angle?

For the difficult-to-cut materials with low thermal conductivity of stainless steel and greater heat influence on the cutting edge, a large helix angle end mill is used for cutting, which helps to extend the tool life. In addition, the characteristics of the finished surface change due to the helix angle. For example, when smooth finishing is required, sometimes a large helix angle type end mill can be used.

However, when using a large helix angle end mill, the cutting resistance will increase, and the force of the right helix angle tool will also increase, so corresponding measures must be taken, such as using a tool holder with high clamping rigidity.

Although the rigidity of the tool can be ensured, small helix angle end mills are sometimes used when the rigidity of the workpiece is low, such as thin plate processing.