1/8 router bit with 1/4 shank vs. end mills

[Jim Mackell]

Looking for slightly longer router bits to mate with butterfly templates from Rockler. Amazon shows a few at about $20. each. "End mills" in the same size are significantly less expensive, but there's no 1/4 shank. Any recommendations?

[ChrisA Edwards]

You can get a 1/4" to 1/8" router collet adapter than will allow you to use 1/8" bits.

https://smile.amazon.com/Engraving-Router-Adapter-Convert-Machine/dp/B00NL7ZQCQ/ref=sr_1_5?crid=28BIX1KSEO0MW&dchild=1&keywords=1%2F8+router+collet+adapter&qid=1606140417&sprefix=1%2F8+router+coll%2Caps%2C159&sr=8-5

https://images-na.ssl-images-amazon.com/images/I/61MX4m8eQbL._SL1000_.jpg
I have a Shaper Origin and use it with 1/8" shank bits down to 0.5mm cut diameter.

[Jim Becker]

I regularly buy 1/8" end mills with 1/4" shanks...I just received two on Saturday from Amazon. They happen to be Yonico branded this time around. They are available in both up-cut and down-cut spiral and generally have a .75" cutting length. I recommend sourcing these rather than using bushings if you can possibly do so.

Edit: I forgot to add that I have an Amana end mill that has a very long 1/8" cutting length with a 1/4" shank, too...it's a bit designed for cutting foam. It's not practical for cutting wood unless it's merely to clean up an edge in a deep pocket. The longer length combined with lateral force too easily can result in a broken piece of tooling.

[Richard Coers]

A major consideration in long 1/8 end mills is getting rid of the sawdust from the kerf. Keep the kerf loaded up and feed too quickly and you will then have a really short end mill. Like as in the end mill snapping off. The other concern is some smoke coming out of the dust. It takes a lot of finesse and multiple cuts to work with thicker stock and long 1/8" bits.