Tool Testing Done Right

Author Michael Deren
July 01, 2009 - 12:00pm

Cutting tool tests performed by vendors are an excellent resource, and I’ve used them many times. They can help your shop accomplish the following:

  • compare vendors,
  • reduce cutting tool costs,
  • reduce machining cycle times, and
  • expand its cutting tool knowledge base.

To make use of this excellent resource, you need to make appointments for the tests with the vendors, have specific projects in mind and allocate the time required to perform the tests. Vendors need to fully understand your application, ship or bring the tools and perform the testing. This may sound simple, but the devil is in the details.

By making an appointment with your vendor, you and the vendor agree on a specific time and place to perform the tests. You will have discussed the project and its goals. It is your responsibility to allocate machine time. This includes the toolholders, work materials and fixtures required for the tests and the personnel to run the machine. Usually, I try to have these resources ready before the vendor comes in, but to tell the truth I have sometimes been guilty of not being fully prepared—not always through my own fault, though!

The vendor is responsible for shipping the cutting tools ahead of time or bringing them on the day of the testing. If any toolholders are required that you don’t have, the vendors should ship or bring them as well. You, however, should have the required retention knobs for the toolholders. In the case of indexable cutting tools, the vendor should also bring the proper wrenches to load the inserts and backup tools, just in case a cutter fails.

Not too long ago, I scheduled a cutting tool test with a vendor for about 1 p.m. The vendor came in, cutting tools in hand. Unfortunately, a job ran late on the machine we were going to use. We tried to tear down and set up as quickly as possible, but it was 3 p.m. before we were ready to start testing. The shift ended at 3:30 p.m., so we had to cancel the test. I felt bad, knowing I had wasted my vendor’s time that afternoon. I apologized and rescheduled for the next morning. The vendor brought his first choice of tooling along with a second choice should the first one fail. We had a productive and successful test.

A few days later, another vendor came to run a test. He shipped some tools directly to us and brought other tools the day of the test. The vendor arrived for the test at about 10 a.m., but the primary cutting tool to be tested arrived at our dock an hour later. It was a minor delay, but a delay nonetheless. The testing went well, however.

The next day, I had a third vendor scheduled for a test—the last day I had available. The vendor arrived promptly, but brought only one cutter. The tool had too many flutes for the application and promptly loaded up in the first pass. That vendor was done for the day. He spent a grand total of 30 minutes in our shop after we had allocated a minimum of 3 hours, with an option for the entire day. He wanted to bring another cutter the next day, but it was too late. He was disappointed, but there was nothing I could do.

By fully preparing for tests, you’ll eliminate lost time during testing. If you have to change your test time, be respectful and notify the vendor as soon as possible. Don’t wait until he gets to your shop, because he could have made other appointments to fill the gap in his day. On the flip side, if your vendor can’t make it, he should contact you and make other arrangements. Your time is just as valuable. CTE

About the Author: Mike Deren is a manufacturing engineer/project manager and a regular CTE contributor. He can be e-mailed at

Related Glossary Terms

  • flutes


    Grooves and spaces in the body of a tool that permit chip removal from, and cutting-fluid application to, the point of cut.


Machinist's Corner Columnist

Michael Deren is a manufacturing engineer/project manager and a regular CTE contributor. He can be reached via e-mail at