The Situation

Not every machining challenge requires customization, which is why GWS Tool Group offers a huge selection of ultimate performance cutting tool options for smaller shops or applications that need them. In this case, a large automotive job shop was looking to improve tool life and if possible, metal removal rate. The application was using ductile cast iron, milling a valve assembly used by several large automotive manufacturers.

The current end mill in use was a ¾” four flute variable helix end mill from a large global cutting tool manufacturer. They were using the mill to profile the part at 2,292 RPM at 36.67 IPM. With a metal removal rate of 1.76 cubic inches per minute,  and due to the expense, the customer was anxious to improve on these results but had struggled to find an alternative off-the-shelf solution that could match the performance of their existing end mill.

Current Process Results

  • Usage: 127 end mills per year
  • Feed: 36.67 IPM
  • Metal removal rate: 1.76 cubic inches per minute
  • Annual tool cost of $24,222.52

New GWS Solution

  • New usage: 127 to just 26 end mills per year
  • 91.49% increase in productivity, 392 machine hours saved
  • Hurrimill® increased feed to 65.32 IPM
  • Metal removal rate at 3.14 cubic inches per minute
  • Annual tool cost of $3,676.52 ($20,546 savings)
  • Tool life: +180%
  • Cycle time savings: $17,647 (392 hours)
  • Total Cost Savings = $38,571.58


Enter the Hurrimill® HGW4 series 1030, from GWS.  A four flute, variable helix, unequal index end mill with full eccentric OD relief, tapered core, FX5 nano PVD coating and rake angle designed more specifically for harder materials and cast iron. It was the perfect tool for the job, and given the customer’s desire to improve metal removal rates, we determined a larger diameter end mill could further help accomplish this goal. We recommended that a 1.0” Hurrimill® be used, and despite the larger diameter the unit cost of the end mill was still 25% less versus the competitor!

The 1” Hurrimill® was run at the exact same parameters as the existing tool, with the one exception of feed rate. Given the larger size and more robust geometry, chip load was increased from 0.004 IPT to 0.0095 IPT, increasing the feed to 65.32 IPM. The new effective metal removal rate was now an amazing 3.14 cubic inches per minute. Perhaps even more impressive was tool life, which increased by 180%! The final savings were staggering including a 91.49% increase in productivity, 392 machine hours saved, $20,546 annual tool cost savings (127 to just 26 end mills per year), $17,647 cycle time cost savings, with a total cost savings of $38,571.58.

In the end, the massive improvement in both cycle time and tool life yielded a savings for just one end mill and operation of $38,571.58.  An eye-opening result for the customer who had never tested a GWS Hurrimill® end mill before, but is now looking to let loose a storm of savings and productivity in the rest of their facility.

Interested in finding out more information about our standard and custom tools? Consider contacting the experts who make Custom Come Standard, and let us find the perfect cutting tool for you. Just send us an email at to get started!

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