End Mill Troubleshooting Guide

End mill tools eventually wear out due to frequent use. Modern engineering, improved materials, and advanced cutting tools have helped extend end mills' lifespan despite the workload they are exposed to. Outstanding manufacturers train their operators to handle cutting tools and common causes of frequent tool malfunction.

Although reliable end mills tools suppliers like SCTools provide a troubleshooting guide, machinists should be aware of the most frequent causes of premature carbide end mills failure. They should also acquire the skills to recognize and correct minor problems. Today, we will discuss common causes and solutions to carbide end mills' problems.

Running the End Mill Too Fast or Too Slow

Inexperienced machinists can have a challenge matching the right machine speed to the end mill types available. They need to internalize the ideal speeds required because running a tool too fast causes suboptimal chipping or tool failure. On the other hand, running it too slowly can cause deflection, decreased metal removal rates, and poor finish—as indicated in the SCTools end mill troubleshooting guide.

Solution

• Use the correct speed
• Slow down on the first bite to prevent progressive chipping
• Cut less amount per pass if you are using the right speed, and chipping occurs

Feeding the End Mill Too Little or Too Much

Another critical aspect related to speed is the feed rate. If you run your carbide end mill tool with a slow feed rate, you are likely to recut chips, accelerating tool wear. If the feeding rate is too fast, you can cause tool fracture. The best feed rate for any job depends on the end mill types and the material being worked on.

Solution

• Use the proper speed
• Adjust to a small cutting amount per tooth if a fracture occurs while using the correct speed
• Regrind in the earlier stages to reduce wear

Poor Machine to Tool Connection

Improper tool holding can cause tool pullout, tool runout, and scrapped parts. The more firm the tool holder's contact with the tool's shank, the better the connection. Shrink fit tools, and hydraulic tool holders offer superior performance over mechanical tightening methods and some shank modifications.  

Solution

• Check the overall condition of your tools, machines, and attachment
• Repair machine or holder
• Replace worn-out tools with durable end mills 

Operating with a Long Length of Cut

A long length of cut (LOC) reduces the strength and rigidity of cutting tools. Sometimes it is unavailable to use LOC because it is necessary for finishing some operations. Generally, a tool's LOC should be the exact length required to ensure your tools retain their original substrate. A longer than necessary tool is more susceptible to deflection, decreasing its lifespan and increasing the likelihood of a tool fracture. 

Solution

• Use proper tool length
• Hold shank deeper if you use the correct tool length
• Stock various end mill types to prevent using the wrong tool length

Selecting the Wrong Flute Count

A tool's flute count significantly impacts your output performance and running parameters. A tool with a low flute count of two to three has a smaller core and larger flute valley. This variable causes the tool to weaken and become less rigid if used on the wrong material. Low flute counts are ideal for aluminum and non-ferrous materials because they help reduce chip recutting. End mills with a high flute count of five or more have a larger core which is great for working on harder and ferrous materials.

Solution

• Use end mill with more or less flute count depending on the material
• Regrind at earlier stages if you are using the correct flute count 
• Add margin if you are getting a rough finish while using proper flute count

Picking the Wrong End Mill Coat

The best tool to use is one with a coating optimized for your workpiece material. End mills sourced from a reputable cutting tools company increase lubricity, slowing down natural tool wear. Other available coatings increase hardness and abrasion resistance. Which coating should you choose?

Contact us today and receive a professional answer from cutting tools experts who will help you choose the perfect carbide end mills coating to optimize your production and extend your end mills tool life.

If you have any questions about carbide cutting tools, end mills, drills, etc. be sure to reach out to us @ sctools.co/Home or call us at (877)737-0987. We help you machine better!