[keithmcelhinney]

I have an old nm-135 with a 3500rpm spindle. I have been running the following :

1/4 3fl carbide end mill 18ipm .07 doc 3500rpm
3/8 3fl carbide end mill 18ipm .08 doc 3500rpm

I need to get new endmills and wondering if I should change. A lot of people suggest using just hss or cobalt. I don't want to slow my cuts down, quite the opposite. I do almost exclusive slot cutting in 6061. Any suggestions would be appreciated. Also if you really like a certain brand..

Thanks - Keith

[SCzEngrgGroup]

Keith,

These machines don't have enough spindle RPM, or rigidity, to really take advantage of carbide. I can pretty much guarantee that HSS tools, properly used, will give you the same, or better, performance than carbide, at about 1/3 the cost. I use nothing but HSS on both my Torus Pro, and my 9x49 knee mill. I've used carbide, but it gained me nothing.

Best thing you can do is buy good, American-made HSS tools, and use a good feeds and speed calculator - like FSWizard or HSMAdvisor (Google them) - to set your feeds and speeds. I've never even seen an NM-145, but I can pretty much guarantee your machine can be probably worked harder than you are working it at present.

Regards,
Ray L.

[skray775]

Went through all this over the last year or so...

After trying several brands I have settled on the Atrax carbide end mills from Enco.
Very affordable and less then HSS in most cases.

I have also tried the Hertel high helix aluminum end mills and like them as well.

[kvom]

I also use Atrax carbide ems from Enco.

[AiR_GuNNeR]

Keith,

These machines don't have enough spindle RPM, or rigidity, to really take advantage of carbide. I can pretty much guarantee that HSS tools, properly used, will give you the same, or better, performance than carbide, at about 1/3 the cost. I use nothing but HSS on both my Torus Pro, and my 9x49 knee mill. I've used carbide, but it gained me nothing.

I pretty much agree with one exception. I like to use carbide for the finish cut on 3/16" dia and smaller endmills as they are much stiffer and for me give a better surface finish.

[rlockwood]

I pretty much agree with one exception. I like to use carbide for the finish cut on 3/16" dia and smaller endmills as they are much stiffer and for me give a better surface finish.

and they're dirt cheap anyway