The Different Types of End Mill Reliefs: In The Loupe TV Short

There are many different types of reliefs on end mills, but which is best for your specific applications? In this episode of In the Loupe TV, join the “Cutting Tool Counselor,” Don Grandt, as he dives into why manufacturers put reliefs on end mills, the different types of reliefs, and which you should be choosing for your next job.
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[@hpfstrawn1071]

Holy cow! That endmill simulation video of the chip forming was incredible to see! I'd love to see more video on that and deep cuts where you'd end up with multiple flutes in the cut at the same time.

[@mjbeardjr]

Keep on making em

[@user-ky6nj9yg9d]

Instead of cylindrical land, some of manufactures make flat relief with angle 2-3 degrees width about 0,1mm, and it work good in non ferous applications

[@danhnguyen435]

Thanks

[@muralinaik6511]

Finally Don arrived! Very informative session..
Thanks a lot...

[@CuttingtoolCounselor]

Better late then never!!

[@jbrownson]

Great explanation, thanks

[@CuttingtoolCounselor]

Thanks much!!

[@MrCNC]

nice job!

[@user-ky6nj9yg9d]

I am never face with con eccentric relief on end mills. I would appreciate if your share in which application better use con eccentric reliefs?

[@CuttingtoolCounselor]

Aluminum and non-ferrous materials are the best to use a small cylindrical margin. These materials tend to grab and can produce chatter if up sharp. ctc

[@user-ky6nj9yg9d]

Con flat relief is good for aluminium in high speeds, but cylindrical margin should be not more than 0,06mm and you should control it. When you manufacture hundreds of end mills this type of relief could be an issue, cause you wheel has wear and make this land wider per mill

[@CuttingtoolCounselor]

You are correct it should be very small in order not to put extreme tool pressure. You will also see a lot of Con-eccentric relief in taps to help stabilize in the hole. This cylindrical margin is much larger. Thanks for the comment. CTC

[@user-ky6nj9yg9d]

@@CuttingtoolCounselor I’m not sure about taps, famous manufacturers like OSG, or YG1 has eccentric relief on taps but not con eccentric. Most of taps has different reliefs on the guide part (tang angle about 0,5deegr, and on the cone about 4 deegr depends on material and tap type. But if you use con ecccentric reliefs your tap can break up easily, because of big torque. Think about it.

[@vinnymagalhaes3879]

@@user-ky6nj9yg9d what is the role of cylindrical margin on end mills? what is its relationship to the diameter of the end mill?

[@CuttingtoolCounselor]

@@vinnymagalhaes3879 First and foremost the Cylindrical margin is the diameter of the tool. Ground during the blanking process and held to a .0004 tolerance. It has no Relief and the the back side of a thin margin is ground away. Mainly used for Aluminum and other non -Ferrous materials. It helps the tool not Grab the material and create chatter. Ctc

[@GoodFoodGoodMood481]

Also depends on the diameter of the cutting tool, Roughing or Finishing applications and other factors. Can be controlled if you are able to do in process measurement and correctly offset the EFF. Also, the wear will be much less if you are controlling the cylindrical grinding/blanking (assuming the tool diameter is less than the shank diameter)