Cutting Steel with Circular Saw

[Jelly]

I've seen mention (and video) on the net of using circular saws (yes the skill-saw type) with TCT blades to cut structural steel sections and plate.

Scant information about blade selection though, I can't escape the feeling that cuting steel with a saw which runs much faster than your average cold-saw or Bandsaw will need geometry different to both conventional multi-purpose circular saw blades and conventional cold-saws.

I know evolution have been marketing mitre saws and blades for this purpose which have a good reputation as a cost effective alternative to Cold-saws for small fabricators, but unclear about what's actually special (if anything) about them.

Anyone got any experience?

 

[TheTiddles]

It’s in the tooth geometry, the thing with a mitre saw is the blade may slow down and stop but it’s unlikely to kick the workpiece back at you or worse the entire saw, however a handheld circular saw might well do that, so I’d not go for it myself.

A reciprocating saw with a metal cutting blade in is “good” for demolition work and very rough cuts. For accurate work I usually order it pre-cut which weirdly is often cheaper than buying full lengths. The right places do super accurate cuts and deliver right to your doorstep neatly packaged

Aidan

 

[TheUnicorn]

in a discussion elsewhere on the forum another member was saying that the evolution saws run slower than a wood only saw

 

[Sandyn]

I use the evolution saw. The blade is designed differently. This is a picture. I think the design ensures that a small cut of metal is taken each time, like a depth stop. The blade works very well, to start with, but wears very quickly. You have to get the correct technique for cutting otherwise it wears out even quicker. It produces a lovely finish when new, but is all over the place once it gets worn. At £25 a time, it's not cost effective, so I have gone back to the angle grinder. Aldi 110mm 1mm thick disks are brilliant and last far longer than you would expect for a thin disk. The evolution saw spits red hot bits of metal all over the place. Up your sleeve, down the back of your neck. The grinder does the same, but just finer and more directional

 

[Jelly]

I use the evolution saw. The blade is designed differently. This is a picture. I think the design ensures that a small cut of metal is taken each time, like a depth stop. The blade works very well, to start with, but wears very quickly. You have to get the correct technique for cutting otherwise it wears out even quicker. It produces a lovely finish when new, but is all over the place once it gets worn. At £25 a time, it's not cost effective.

It looks like the same concept as chip limitatiom tooling in a spindle moulder... I can see how it would both wear badly and be impossible to rectify with a regrind.

Based on your honest appraisal I'll stick with a grinder and patience until have the cash for new gas bottles.

Shame, as the idea seems quite attractive.

 

[jimmy_s]

I got one in the summer, mainly as I needed something for fabricating steel portal frame to replace the conservatory with a sunporch - with a ridge beam holding up the roof. I have used a chop saw before for prepping steel for welding with a big cutting disc similar to an angle grinder cutting disc. The disc tends to wander, especially cutting mitres. I havent got the space for a power hacksaw so got a chop saw with a carbide tipped blade.

Ive been really impressed with it I was using it to cut 80mm box section with a 5mm wall and it went through it like a knife through butter. The cuts were very clean and with no issues with the blade wandering.

I've also been using it to cut up old sarking boards/ cls and tile battens etc for firewood as its a lot easier and faster than the chainsaw as hitting a nail is not a problem.

I got the industrial type spec evolution with a 350mm or there abouts blade

 

[Sandyn]

I got the industrial type spec evolution with a 350mm or there abouts blade

The one I have is smaller. I think 255mm blade. It does cut really well when its new. Have you cut a lot of metal with yours? The teeth still feel sharp, but it just doesn't cut as well.

I did get a diamond blade for it for cutting paving blocks. Now that was a different story. Like a hot knife through butter. great for cutting accurate angles and able to cut really thin slices. I would rate it excellent with a diamond blade on concrete.


I also have a Evolution fury twin (hand held) which has contra rotating blades. I used it for cutting up an old shed I had, full of nails. it was good, but would get bogged down if you cut squint. It cut through metal very well. I had a side of the shed leaning on my step ladder. I was cutting the wood and sliced my step ladder without realising it

 

[TFrench]

Evolution saws are slower spinning than a normal one. We have a rage2 (I think - the big one like the poster above) for chopping up pallets at work as it doesn't matter if you hit a nail. I've not really tried to use it much to cut plain steel as the blades are pricy.

 

[jimmy_s]

Ive not used mine that much to be fair. Mainly up the 80mm box section and some 40x10mm flat bar, and a fair bit of firewood - but that doesn't really count.

To be honest for me its been worth it for processing firewood as its so much faster than messing about with a chainsaw. The conservatory was sepele. I've kept what was salvagable and cut the remander up for firewood and also having stripped part of the house roof which was tiled and replacing wtih slate back to the sarking boards so I had a lot of tile battens which were also cut up on it, plus some CLS that was under a flat roof.

 

[Jelly]

for chopping up pallets at work

Out of pure curiosity why chop up rather than sell?

We've been seeing £2 per Euro and £1.25 per standard at points last year, if you rack them up out the way then get a lorry load out every so often it soon adds up.

 

[TFrench]

They're the pallets our sheet metal comes on, not euro pallets. The wood is chunky enough to be worth putting on the fire!

 

[Sandyn]

Ive not used mine that much to be fair. Mainly up the 80mm box section and some 40x10mm flat bar, and a fair bit of firewood - but that doesn't really count.

I can't decide if I'm being too critical about the saw blade. It did cut very well to start with. It's difficult to say how much metal I cut with it, but it wasn't a lot. I thought I had been trying to cut too quickly, so when I put on the second blade I was very careful to cut slowly, but that didn't help. With both blades, I do remember thinking...'is that blunt already?'

It would be ideal for cutting scrap wood with occasional nails.

 

[julianf]

I use a rage something or other (the one with a 12" or so blade - the largest one) for hacking up fire wood.

I try hard to avoid nails with it. Indeed, pretty hard indeed, as the blades are not cheap.

If i wanted to make nice cuts in ferrous, i would use my Rapidor Minor (google it, if youre in any way curious) but thats not one that you can buy at screwfix.

Failing that, i think i would use an abrasive wheel, either on a hand grinder, or some sort of mitre saw thing

I have a plasma cutter also, but rarely use it - generally i find the hand grinder gives me better results than the plasma.

 

[julianf]

For accurate work I usually order it pre-cut which weirdly is often cheaper than buying full lengths.

I cut metal for work, but the above is very true.

Last time i bought some extrusion, even though i was being charged per cut, having the supplier cut it meant zero waste at this end (they charged by the length, so, effectively, if i bought full lengths to chop here, id have been paying for the offcut material also)

The reduction in transport costs (of shipping shorter lengths) also offset the cutting charge.

I cant remember exactly but i put it all into a spreadsheet, and there was virtually no difference either way (may have been cheaper, may have been more, but there was pocket change in it) between me cutting it or them.


But....

Everyone has different ideas of accuracy. So if its important to the OP i would also concur that you need to find the right supplier for your own expectations.

 

[Hornbeam]

I use a makita saw with metal cutting blade for cutting profiled metal sheeting in work but that is up to about 1mm max. It cuts really nicely and very accurate but spits metal particles everywhere (face shield an absolute must). For cutting box section etc I would use a cut off saw with a metal cutting disc

 

[TheTiddles]

Metals4u is who I use.

I had the question about accuracy so rang them up and the first person I spoke to (who I wasn’t expecting to have that information off the top of their head) gave me the cutting tolerance per process used. What I got delivered was far more accurate and there were two additional pieces that I hadn’t ordered there too, on very careful measuring I found they were a fraction of a mm under size of one of the sizes I’d ordered, so they’d included them for free. Order to delivery was 2-days during lockdown

Aidan

 

[Spectric]

Always used to use a makita with a grinding type disk to cut steel, not a blade with teeth but technology moves on.

 

[Sandyn]

Always used to use a makita with a grinding type disk to cut steel, not a blade with teeth but technology moves on

Do you use Makita disks, or have you tried others?

 

[Spectric]

I used some Makita blades but also a lot of Bosch & Tyrolit as they were more easy to come by locally, again they were not toothed but these days diamond blades are being used more often but not cheap..

 

[Sandyn]

I used some Makita blades but also a lot of Bosch & Tyrolit

Thanks. I will give the tyrolit a try, they do a good selection and some of the 350mm disks are available at 2.5mm thick. Other cutting disks are too thick.