Thread: Cutting Metal Sheets with Circular Saw

Hi Iaan,

I've got a Makita blade for cutting mild sheet steel of max 2mm thickness. Cutting corrugated iron is one of its specified applications. It's No A-86446, is 185mm (71/4") Dia and has 70 carbide tipped teeth. I don't remember where I bought it but the price sticker says $115.00.
Cheers,
Geoff.

Many years ago my father-in-law cut galvanised iron sheets with a special blade in a monster B & D circular saw. From memory the blade had "square" teeth and literally burnt through the iron. I think your saw needs to have a metal guard, not plastic, over the blade as the 'chips' are red hot as they come off the iron.
Hope that makes sense and is of some help.

Roofers usually do it with tin snips when it needs to be done but it can be cut with a power saw. Terrible noisy messy job though. Make sure you sweep the sheets down well afterwards because any swarf remaining will rust and cause rust stains on the sheet. We used to use a regular blade - no tungsten teeth - mounted backwards. Definitely best to buy one of the blades recommended above though

Others will advise more but I was told not to cut colourbonded metals with a saw or grinder as the blades generated too much heat which affected the colurbond causing it to recede from the cut exposing the metal to the elements, in other words, it rusted quicker than if it had been cut with snips.

Not sure if the above is totally accurate but it seemed to make sense.

I ended up buying a nibbler, which did the job but was noisy and the tiny half moon clippings were a pain to pick up. Thankfully I have a large magnet which I swung on a cord.

Years ago when I was working at Wreckair the shed hire dept tradies used a panel cutting saw blade similar to this.....they called it a beta blade, from memory....

http://www.austsaw.com.au/products/panel-cutters

might help??

Originally Posted by Bob38S

Others will advise more but I was told not to cut colourbonded metals with a saw or grinder as the blades generated too much heat which affected the colurbond causing it to recede from the cut exposing the metal to the elements, in other words, it rusted quicker than if it had been cut with snips.

I have heard something similar but it could be urban myth. I know that grinders and saws were banned from the handful of roofs I've ever worked on because of the swarf. Sheet roofing is very easy to cut with snips and can be done in situ, like when cutting valleys, with minimal fuss. I've been using a lot of corro around here on various sheds and fencing and I always cut it with the 14" Gilbows. For rough rip-cuts, I use a bit of fencing wire tied to a lump of sleeper which you pull up through the tin.

There are a couple of types of nibbler: the shear type and the punch type, which it sounds like you have got. I have one of them too and they are great for cutting sheet, especially if the lines are not straight. They are a bit messy and noisy but I would choose them over a saw or grinder any day. Shears leave no swarf but they are a bit less manoeuvrable.

Thanks all for your suggestions.

I just had a look at what's available at Masters... The conventional option would be to buy a carbide steel circular saw blade for cutting iron based metals, such as a this:

https://www.masters.com.au/product/9...lade-48t-230mm

$100 is more than I paid for the circular saw in the first place though.

How about simply using a standard frictional cutting disc like this?

https://www.masters.com.au/product/9...230x25-4x2-8mm

Have anyone used these in a handheld circular saw?

I should mention that the old Hitachi PSU-9 is pretty solid with covers and protector plates etc all being metal.

http://www.bunnings.com.au/gilbow-30...snips_p6012140

Only $45.