Tool Life Calculator | Cutting Time and Wear Guide

Tool life is a length of time that a cutting tool will remains functional before the edge of the tool becomes worn enough to no longer complete the required cutting task. The balances of heat, force, and the material of the tool itself determine the life of a tool. If the amount of heat or force applied to the tool are increased, the life of that tool will decrease.

However, if these variable can be managed, the life of the tool will increase. Taylor’s equation is used to mathematically calculate the life of a cutting tool. The equation utilize the cutting speed and an constant value to calculate the edge wear that will occur.

Factors That Affect Tool Life

In the equation, the cutting speed is raised to a specific power. If the cutting speed is increased, the tool life will decrease. However, if the cutting speed are lowered, the tool life will increase.

Furthermore, because this is a non-linear equation, a small decrease in the cutting speed will result in a large increase in tool life. The material that is being cut will impact the life of the tool. Materials like aluminum is softer than others, such as stainless steel.

Due to the soft nature of materials like aluminum, workers can utilize higher cutting speeds. However, cutting speed will need to be decreased for materials like stainless steel because the increased heat and resistance that is created will impact the tool’s life. Therefore, cutting speeds need to be selected according to the type of material that is being cut in order to maximize the life of that cutting tool.

The material of the cutting tool will also impact the tools life. For instance, carbide tools can withstand more heat than tools made of High Speed Steel (HSS). Additionally, tools with coating will provide more protection for the edge of the tool.

For instance, workers often use Polycrystalline Diamond (PCD) tools for cutting wood or non-ferrous metals. Additionally, the number of flutes that is included on the tool will also have an impact on the life of the tool. Tools with more flutes can cut at higher feed rate.

However, the increased number of flutes will allow heat to building up within the tool. The feed rate per tooth, or chip load, will impact the life of the tool. If the chip load is set to be too light, the cutting tool will rub against the material, leading to the wearing down of the tool edge due to polishing.

If the chip load is too heavy for the material, the force that is placed onto the tool edge can lead to the tool edge crack. Therefore, the chip load must be heavy enough to effectively cut the material, but light enough as to not place too much force onto the tool edge. Furthermore, the depth at which the tool is cut into the material will also impact the tool life.

Axial depth will linearly impact force. However, radial engagement will impact the force in a nonlinear way due to chip thinning. The use of coolant will help to increase the life of the tool.

Coolant will help to reduce the amount of heat generate at the edge of the tool, reducing wear by 10% to 20% on difficult jobs. However, coolant is not always effective in all cases. For instance, coolant can gum up acrylic.

There are a variety of mistake that will decrease tool life. For instance, if a tool is running at the maximum RPM for that tool, but the surface speed is not checked before starting the tool, the tool may be subjected to force and heat that will decrease its life. Additionally, if heavy engagement is used but climb milling is not utilized, the cutting tool will experience increased torque, decreasing its life.

If the number of flutes of the cutting tool is not considered when cutting sticky materials, the tool will experience crater wear. Finally, if chatter is experienced with the tool, the feed rate should of been decreased by 20% to reduce the force of the cutting tool. There are a few tradeoffs that can be made to increase tool life.

For instance, if the desired outcome is to increase the number of part that are cut with a specific tool, the cutting speed can be decreased by 20% which will quadruple the tool life. Additionally, an engagement level of less than 50% can be used to allow for more aggressive feed rates due to chip thinning. Finally, one should inspect cutting tools regularly to ensure that the tool life is still within acceptable limits.

For instance, if the cutting edge is not sharp, the tool will burn the material and its life will be exhausted.