Atlas Mill - Marvin attachment bit source

[john.kovalcik]

Hi,

Did some searching on the forum but haven't seen what I'm looking for - hoping some direction can be given. I have an Atlas benchtop mill with the Marvin vertical head. I'd like to buy some new bits (or at least one new, sharp carbide bit with a shorter cutting face - the shank of existing bits I have is 3/8 with a flat spot machined into them. Seems like should be easy to find - any recommended source/manufacturer? Home/hobby use - learning - so price point is definitely a factor (although I did say I was looking for a Carbide - most expensive). Just bought a bit off McMaster Carr - paid a lot and won't work right b/c it's 1/4" shank (I messed up) and it won't mount properly in the head - the set screw drives it to one side and it doesn't spin on a center axis. Anyway - hoping someone can throw a bone and give some recommendations for me to research online. Thank you.

 

[markba633csi]

John: Try Amazon, Grainger, Zoro tools, Little Machine Shop, Ebay, Shars
3/8" shank is a very common size; some are flatted and some not
With your machine I would choose cutting diameters of 1/2" or less.
Choose center cutting types if you need to plunge cut; non-center cutting can only cut sideways
2 flute clears chips better (for pocket cuts)
3 and 4 flute gives smoother finishes with less vibration
Carbide tools are brittle, not sure if I would recommend those for your machine
because of the relative lack of rigidity
Cobalt and HSS would be good choices, they are tougher, less likely to snap