Cutting 1cm Alluminium circles

[Ash240]

Will a bimetallic hole saw cut 7cm circles out of 1cm plate?
I need to make some heatsinks. Just got the sheet today. If I pick the correct speed and lubricant would this work?

[RayG]

Hi Ash,

I'd give it a try and see how it goes, the best lubricant for cutting aluminium is metho, kerosene is a good second. Buy a squeeze bottle and keep plenty pooling around the cut.

Some aluminium alloys can be hard to cut, they are gummy and soft and will probably stick to the teeth of the holesaw. So it depends on the alloy as to how well the holesaw will do. You might have to keep backing it out to clear the swarf.

As far as speed goes, I'd keep it slow for a start, the surface speed with a 70mm diameter cutter will be high enough anyway.

Regards
Ray

[Gavin Newman]

Another thing to try which works well for me on deep holes in steel for me is to start the cut with the hole-saw then once you are in about 1mm to use a drill, the same diameter as the width of the saw kerf to drill a series of holes down through the material in the saw cut - this helps prevent the swarf from getting trapped when you complete the hole-saw cut. I've never tried in on ally but I can't see why it wouldn't work for that as well.

[Stustoys]

Hi Ash,
Another thing you could try, put the circumference of the cut so it breaks the edge of the material, that will let the swarf fall out as well.

Stuart

[Master Splinter]

I've found this handy to have in the spray can, and it's thick so it doesn't dribble off everywhere like kero

Trefolex CDT Cutting Oil from CRC (http://www.crcind.com.au/catalogue.nsf/web_brands/Trefolex+CDT+Cutting+Oil?openDocument)

[Dave J]

I am not sure if you can return it, but you would have been better off with 70mm round bar and cut 10mm slices off on a bandsaw. It would be lot less work and you could even have the supplier cut them for you, for a small charge.
If your stuck with it, do you know what grade it is?

Dave

[BobL]

I am not sure if you can return it, but you would have been better off with 70mm round bar and cut 10mm slices off on a bandsaw. It would be lot less work and you could even have the supplier cut them for you, for a small charge.
If your stuck with it, do you know what grade it is?

Dave

For 70 mm I would use a negative rake table saw blade. There would a fair bit of kerf loss but it produces outstanding finish. In this case using hard wax on the blade works a treat.

[Ash240]

I haven't bought the saw yet. I do have a small bandsaw and was thinking about cutting the plate into squares and then trimming back on the bandsaw then grinder.
I do not want the center cut :( They will be heatsinks. I COULD get by if I had to have a center hole.
No idea of the grade as it was free. I have been trying to find some scrap to use and none of the place I have looked at want to sell it. Was doing some work for an older woman who's husband died some time ago and happened to find it while I was looking for something else at her house.
I have 4ltr's of some castrol cutting fluid so I will give that a go and a few other products to see which works best when the time comes.

[Ash240]

How well would the table saw cut circles though? 7cm's is likely too small for me to want to have my hand that close cutting metal.

[Com_VC]

How many do you need to cut? A good quality hole saw would do it with ease but will cost you especially if you need to buy an arbour as well. I'm not sure how well the holesaw will work without a center hole, maybe on a drill press?

Have you consider visiting the laser cutters if you have any where you live, they would have plenty of circles in different sizes i'd imagine.

[Dave J]

How well would the table saw cut circles though? 7cm's is likely too small for me to want to have my hand that close cutting metal.

The saw was sugested to cut the round bar if you got some.

Dave

[BobL]

The saw was sugested to cut the round bar if you got some.
Correct


I haven't bought the saw yet. I do have a small bandsaw and was thinking about cutting the plate into squares and then trimming back on the bandsaw then grinder.
Grinder and Ally ?? - that's not a good combo. :no:

[Ash240]

I will cut quite a few so the hole saw is a good option if it works :) My drill press is up to the job.
I will ring around laser cutters next week if any are open as I do want quite a few holes cut.
Using a grinder and aluminum disks has done an ok job on other projects and I also have a disk/belt sander which I could finish up with.
I guess I have quite a few options once they are roughed out if the hole saw does not do the job.

[Ch4iS]

I'd also suggest getting a quote from a waterjet cutter, and try getting a quote for if they supply the material, in the past I've found the difference in price negligible.

[Ash240]

thanks for the help.
Since I don't have a hole saw yet. What brands should I look at and where is a good (cheap) place to buy? I may even get it shipped over from the USA as I could buy a set likely for much cheaper than a few singles here.

[wodstok]

you could always take it to a sheet metal shop with a laser or a turret punch and they would do it for u.

[RayG]

thanks for the help.
Since I don't have a hole saw yet. What brands should I look at and where is a good (cheap) place to buy? I may even get it shipped over from the USA as I could buy a set likely for much cheaper than a few singles here.

Hi Ash,

Sutton Gamflex are ok, and fairly readily available..
SKH are a bit better, but I'm not sure I've seen one that would do 10mm thick, they are mostly for thinner sheet metal.

Depends a bit on how much you want to spend.. :)

Regards
Ray

[Com_VC]

Sutton is a good brand to go for, most industral places stock these, even bunnings. You will pay for it though. If you arent in a rush I would keep my eye on ebay as you can usually pick them up fairly cheaply.

Blu-mol make good hole saws as well and they are a usa brand.

There is also starrett, I have not used there hole saws but they are a well respected brand so should be ok with those.

I've used the sutton and blu-mol saws in industrial applications and haven't had any issues. The sizes I have used have ranged from 25mm up to 152mm. Mainly in aluminum rangeing from 5mm - 12mm but on rare occasions on steel up to 8mm. Most of the time driven by a air drill.