what aluminum has the smoothest cutting properties

[replicapro]

I don't know what type of aluminum Im working with, as it is scraps to practice with. It seems that no matter how fast the machine is going or how slow I go, the cuts are rough.

I switch over to 360 brass or even cast blocks of resin, and I get nice smooth cuts. Steel cuts the smoothest of all.

So is all aluminum the same?

[DAB_Design]

In my experience, for the most part, most common alluminum alloys machine very similar. I have seen some that are more "gummy".

Out of curiousity, what type of cutter are you using? If it is a facemill, does it have a positive or negative rake?

[replicapro]

Im using some of those micro sized ones I picked up on ebay. You know the ones where you get a mixed bag of 70 end mills for $20

However I also tried it with some regular 4 flute and got the same results. Rough on aluminum and smooth on brass and steel. So I guess I just have to find out what type of aluminum is most dense or something.

[DAB_Design]

What speeds and feed have you tried?

[replicapro]

up to 2000 rpm

[Ken_Shea]

replicapro you need to increase the speed, do not know what size cutter you are using, type of mill, feed or type of cut but you may need to slow the feed down and be sure and keep the chips out of the way which may well be most of the problem, best to flood them out or blow them out with air, however you do it keep them out of the way. I have got the best cuts using a aluminum cutting carbide cutter.

Ken

[HuFlungDung]

T6061 aluminum alloy is nice to machine. There are other grades such as "utility" which are gummy as hell.

You should definitely find a way to apply lubricant when milling aluminum, as this will help greatly. Although you can cut it at high speeds, it still gets quite hot, and since its melting point is not all that high, the chips tend to weld together, and to the cutter. Lubricant will help keep the chips flowing.

[sendkeys]

im told fortal is one of the best.

like stuff at http://www.mousebar.com/fhome.html or on ebay . just do a deja.com search get some reviews.

[DAB_Design]

Originally posted by sendkeys im told fortal is one of the best. like stuff at http://www.mousebar.com/fhome.html or on ebay . just do a deja.com search get some reviews.

For those prices, does it cut itself?

Not sure if it's just the area I live in, but 6061 last time I checked was around $1.35/lb (delivered if you ordered enough).

[metlmunchr]

If you dig around a bit, you'll find Fortal is just a name for a French manufactured 7075 alloy. Internet hucksters have attempted to create some mystique around it in an attempt to sell scraps and cutoffs at extremely high prices. If you can find it, 6262-T9 will make you think you're in heaven as far as machining goes. It has the corrosion resistance properties of 6061, slightly higher strength than 6061, and the machining properties of 2011 screw stock.

[duluthboat]

It often is not the alloy in the aluminum that makes it hard to machine but the hardness. If the stock is marked it might be something like 7075 T-6 351. The hardness is the number after the T which tells you the hardness. It runs from 0-9, soft to hard. T-0 is so soft it’s like trying to machine gum. Very sharp tools and special cutting fluid is a must with soft aluminum. T-7 is common and is very nice to machine.

Gary

[sendkeys]

dab_design.. ya its a little pricey but i seen it on ebay for cheaper


Metlmunchr ya for what i seen you're right about it being basicly 7075 . but here what one person said ona nother board. If there right or not im not sure.Also your right about them trying to get top dollar but you can find cheaper stuff

Posted by person another another forum The statement about the nature of Fortal vs. 7075 (i.e. chemistry) is essentially correct. Like the QC-7, Fortal is basically off-spec 7075, but if I recall correctly, Pechiney has a process to manufacture a product with high properties that are essentially the same throughout the plate. In thicknesses over 4", this is very important, as 7075 tends to get "gummy" towards the center of the plate.""

So guess it would only really metter on cut off bigger then 4inch.