Machining Steel With Aluminum Feedrates

- Dec 01, 2017-

We receive plenty of press releases, but when we saw one claiming an endmill that could machine steel at feeds and speeds usually used with Aluminum, we had to investigate further.

Primary Cutter, LLC introduced the SUPERMILL TOMCAT 5 flute carbide endmill line designed to run at high RPM and high feed rates providing rapid stock removal. Utilizing unique tool geometry design, TOMCATS are capable of feed rates of 200 IPM on Steels, Alloy Steels and Stainless Steels. We contacted them and they were kind enough to send us tool for testing.  The results are in… and we’re impressed.

Our test shop pulled up a program for a repeat job with an established program and baseline for our tests.  The old part program called for machining 1018 carbon steel using a 4 flute, 1/2″ coated carbide cutter at 3800 RPM, 30 IPM, .25″ Axial DoC and .25″ Radial DoC.  The operators were quite comfortable with these numbers and cycle times kept the front office happy.  When we began to tell them the suggested feeds and speeds for the SUPERMILL TOMCAT, we didn’t even get beyond mentioning 6000 RPM without hearing scoffs and chuckles.  The looks of doubt continued as we told them to start at 150 IPM, .500″ Axial and .050″ Radial.  These truly were feed and speeds reserved for cutting aluminum.

220 IPM finish on Top. 175 IPM finish on bottom. Click to Zoom.

With the new feeds and speeds plugged into the program, everyone took a step back and squinted their eyes as the operator hit start for the first time.  “BUTTER!!!” was the first comment that came 30 seconds into the program.  Yes, smooth as butter indeed.  The mill hummed with the sound of faster cycle times and greater profits.  “Bump it up”, came from someone in the group.  The operator glanced at the foreman, watching for a head nod to give him the green light.  Everyone squinted and leaned back each time the operator pressed the +10% feed override button, but the churning of the butter continued. We comfortably reached 220 IPM before the Haas MiniMill started nearing max HP.

We could have easily continued to run at 220 IPM but we started to see a little too much of the machining marks.  We brought it back down to 175 IPM and were satisfied with the finish.  Keep in mind that we also broke a machining rule and used the same tool to rough and finish the part… One less tool change to worry about.

Should have stayed with the suggested parameters

Our only hiccup came when we ran the tool using the old program that was meant for the older tooling.  We ended up with a few wear marks in a couple flutes.  We knew this came after seeing no wear with the test program.  That’s our fault and just goes to show that following directions leads to optimal results.

The results:

  • RPM increased from 3800 to 6000

  • Feedrate increased from 30 IPM to 175 IPM

  • Axial Depth of Cut doubled from .250″ to .500″

  • Radial Depth of Cut was cut down by 20% from .250″ to .050″ but…

  • The overall cycle time was CUT IN HALF!!!!

Needless to say, our test shop was extremely pleased with the results.  The most difficult part of the test was getting the tool back from the shop for photos!  Buy one to see for yourself in a 3/4 LoC or 1-1/4 LoC or see more sizes here.