Historically, slotting with a 4 flute end mill was a no go!
This is down to multiple reasons but mainly due to swarf evacuation and vibration. In recent times, the technology of modern-day cutting tools has come on leaps and bounds, meaning it is now possible to slot with selected high performance 4 flute end mills.
Using the correct 4 flute end mill to slot adds strength to the cutter, which allowing you to push the cutter harder without seeing any chatter or clogged flutes. You can really take your performance to the next level but I would speak with our technical team beforehand to make sure everything (including your set up, machine power and work holding) is adequate.
We offer various end mills which you can slot up to 1xD in Steels <45HRc, Stainless Steels, Exotics and Cast Iron in several ranges including: