Carbide tools for Aluminum?

[Rich05]

My mill does not run too fast 3,500 rpm tops. Question is should I be buying carbide.

[dertsap]

it depends upon what type of work your doing , carbides have come down considerably in price so they are much more affordable and have a number of benefits over hss , tool deflection is less with a carbide and wear is generally better as well ,cut depth , tool engagement etc , but carbides not as forgiving as hss if the table has a bit of slop to it . I think it's good to have both , many may say differently but to each his own, i think most of us tend to know what will be best for our own applications . i have a wide array of carbides that i can pull off the shelf when i need one and it's something that i do whenever i need one but right now my small mill in my workshop has a 1/2" 3 flt hss in the spindle , I like to use hss as a general low cost tool that i have no concerns with abusing

[Rich05]

thanks for reply, good info.

[MadMax]

I'm not sure, but there may be differences in adhesion between carbide and HSS. One might not pick up as much built up edge than the other. Personally I like carbide. If I ding an edge in a tool changeover, I swap or turn an insert and don't even have to retouch or grind. If I have a coolant failure do to a plugged coolant port, I usually find that the carbide trucks along decently well, but you can overheat HSS more easily.

[Hayworthmilling]

What kind of mill and how much hp?

On most manual machines 2hp and under, HSS 4-flute endmills work fine. No need for carbide, and no need for 2-3 flute "aluminum geometry" endmills either since you can't really clog the flutes without more power. Just use plenty of WD40.

[CaseyCAM]

Originally Posted by Rich05 My mill does not run too fast 3,500 rpm tops. Question is should I be buying carbide.

Well running 600 rpm on steel is not unheard of... 3000+ rpm is fine for cutting aluminum with carbide.

Also, I use carbide on aluminum without a hitch. You'd think that because its so brittle it'll snap but i've had great luck with it. A good suggestion would be to use 2flute end mills. 4-flute will be more opt to "gum" up with aluminum.

Also, if you don't mind spending a little more cash get 7000 series aluminum (aircraft grade) its got a "crisp" cut chip, not as gummy as perhaps 6061.

[Billet Sean]

Originally Posted by CaseyCAM Also, if you don't mind spending a little more cash get 7000 series aluminum (aircraft grade) its got a "crisp" cut chip, not as gummy as perhaps 6061.

To add to that, Copper & Brass has a 6262 alloy that is awesome to machine and is priced between 6061 and 7075.
Sean

[kling8]

I would use carbide without question. They have carbide tools for cutting aluminum, I use these daily. I would recommend a 3 flute aluminum carbide end mill on tool dia. .25 and larger.

[Geof]

If you choose to use carbide get the micrograin high helix type with the polished finish for aluminum. They do give a nicer finish and they do clog less easily than regular carbides. Don't worry about getting any coated carbides.

Always use some form of lubricant or coolant. I know a lot of people suggest WD40 and it does work but not as well as a proper water mixed coolant which is easier to clean up. Just get a plastic spray bottle and fill it with the coolant mix. Alternatively use the coolant straight and just brush it on along the line of the cut; before turning on the machine!!