What does the helix mean for solid carbide cutters?

Helix: 30°

A milling cutter with a helix angle of 30° has some specific properties and advantages. The lower helix angle concentrates the cutting forces more along the axis of the cutter. This can be useful when machining hard or brittle materials, such as hardened steel, as it helps to minimise the risk of lateral forces and resulting tool breakage.

In addition, cutters with a 30° helix angle can be beneficial when milling pockets or deep slots, as they usually provide better chip control. With a smaller helix angle, chips can be removed more effectively from the cutting zone, reducing the risk of re-entry or clogging.

However, cutters with smaller helix angles generally generate more heat than their counterparts with larger angles because the chips are held closer to the cutting edge. Therefore, they should be used with appropriate coolant strategies to prevent excessive heat generation and premature tool wear.

Helix: 35°

A cutter with a helix angle of 35° represents a middle ground between cutters with smaller and larger helix angles. It provides a balance between the ability to minimise axial forces on the tool (as with cutters with smaller helix angles) and the ability to provide effective chip evacuation and heat management (as with cutters with larger helix angles).

A 35° helix angle can be a good all-rounder for different materials, being able to be used on both hard and softer materials. It provides a balance between the stability and strength required for machining hard materials and the good chip evacuation desirable for softer materials.

In addition, cutters with a 35° helix angle can help reduce heat generation during the milling process and extend tool life compared to cutters with a smaller helix angle.

However, it should be noted that the optimum helix angle depends on several factors, including the material being machined, the type of milling operation (e.g. roughing or finishing), the machine tool and coolant conditions.

Helix: 45°

A cutter with a helix angle of 45° is a good compromise between cutting performance and heat dissipation. It is well suited for a wide range of materials and applications.

Versatility: A 45° helix angle is versatile and suitable for many different materials, including medium-hard steels, aluminium, and other non-ferrous metals.
Heat dissipation: The 45° angle helps to dissipate heat effectively and thus increase tool life. This is especially important when machining materials that tend to generate a lot of heat.
Cutting forces: A medium helix angle such as 45° helps to balance the cutting forces between radial and axial forces, which reduces the stress on the tool.
Chip evacuation: A 45° helix angle promotes chip evacuation, which is particularly helpful when machining long-chipping materials or when roughing.