Machining 1050 Grade Aluminium

[Steve WithnellParticipant @stevewithnell34426]

I have some 2mm aluminium sheet I bought to make an instrument panel.   It happens to be 1050 grade and I’m struggling with feeds and speeds.    Running a brand new 3mm carbide cutter at 7000rpm (Sieg KX1 max) and pushing at 125mm/min,  its cutting   with some pretty horrible burrs, almost like the Al is plastic and melting, rather than cutting.   It took me longer to de-bur than to machine!  125mm/min isn’t exactly motoring, but 1050 is a very soft material about 20HB.

Any thoughts on speeds and deeds, cutter types etc?   What I have got wrong…

Many thanks

Steve

[John HaineParticipant @johnhaine32865]

Wrong material for machining!  References say it is good for forming and welding but has poor machinability leading to clogged cutters.

[JasonBModerator @jasonb]

It’s gummy stuff.

If it were 6082 I’d be feeding at 600-700mm/min with an uncoated cutter with high helix and paraffin.

[Dave HalfordParticipant @davehalford22513]

The alloy is melting less speed and try paraffin

[Neil LickfoldParticipant @neillickfold44316]

You want to use a single flute Aluminium cutter.  Try running around 3k to 5k rpm. Feedrate of 0.01 to 0.03mm per rev.

Cut depth of around 0.5 to 1mm. If clamped well, should be able to cut at the full depth of the sheet.  I use a cutting oil from Blaser CF35.  It also helps to have a vacuum cleaner nozzle mounted to draw away the swarf, and have a light airblow mounted to direct chips to the vacuum port.

The near pure alloys are gummy. I avoid the kero because of it’s flammability.  Water with some dishwashing detergent, also works well for these gummy alloys. Drilling a start hole also helps a lot. But I never recommend an end point hole to be drilled. Breaking through the hole can sometimes cause problems.

Cutting over some sheet wood, and then clamping the sheet either side of the cut also helps with cutting thin plate. Another way is to use double sided tape to hold the material to a painted or sealed material like custom wood sheet.

[Ian Johnson 1Participant @ianjohnson1]

I have machined some parts from soft aluminium on my KX1,  with similar horrible results,  then tried a single flute, diamond like coated (DLC) carbide cutter, made for aluminium and soft material like laminate plastic and wood.  Plenty of paraffin/ wd40 and played around with the speeds and feeds, slowed down to about 3000rpm and increased the feed rate.  Very little burrs and clean cuts with the chips flying off.

Trying to get a better grade of aluminium sheet is difficult,  until you get above 4 or 6mm thickness.

Regards IanJ

[SillyOldDufferModerator @sillyoldduffer]

As 1050 isn’t meant to be machined this is a mild example of tool-abuse!   Though soft Aluminium alloys can be drilled and sawn, they’re intended to be punched and folded, not milled.  The alloy is deliberately soft for making radio chassis and instrument panels, but not by milling.  Different processes used: box-benders, shears, and punch machines etc.   Sheet metal techniques.

Needs must when the devil drives though. I’m poorly equipped for sheet metal work.   Difficult materials can be milled,  just more trouble.  If Aluminium sheet must be milled better to find a harder Alloy, but not if the sheet also has to be bent…

Dave

 

[Steve WithnellParticipant @stevewithnell34426]

Thanks for the excellent replies!    I have more to do and as IanJ commented, it’s difficult to find an appropriate grade.

So sounds like single flute uncoated cutter and slow down with appropriate coolant and make sure the vac is clearing the chips 🙂

[JasonBModerator @jasonb]

6082 T6 x 2mm cut to size here or here

Don’t know what size you need but there are offcuts and small sizes of the same listed on ebay

[Steve WithnellParticipant @stevewithnell34426]

Thanks Jason,   really helpful.  I’m typically using 150mm x 300mm sheets and assumed I was buying 6082 which turned out to be a bad assumption…

Steve

[Paul LousickParticipant @paullousick59116]

I recently tried milling aluminium plate (unknown grade) with a new carbide cutter and had similar results. Changed to a sharp HSS cutter with excellent results.

[Author]

Posts