Metal Cutting

[kiwi2]

I was in the hardware store the other day and they had hand held circular saws on sale which had two blades which counter-rotated. The blades were tipped with tungsten carbide. The writing on the outside of the box listed the materials that could be cut, one of which was steel. Has anyone used these saws to cut steel plate?
It seems unlikely to me but I recently used my old skilsaw with a tungsten carbide blade to cut some 5/8" aluminium plate and that worked OK.

 

[Ozwelder]

It seems unlikely to me but I recently used my old skilsaw with a tungsten carbide blade to cut some 5/8" aluminium plate and that worked OK.

Hi Kiwi
These units you describe have bobbed up in the chain stores here in Australia. I would avoid attempting to cut any metal with your saw other than ali.

When an incorrect saw tooth angle is fitted the saw blades can kick badly. I have been a metal fabrication tradesman for nearly fifty years and seen my fair share of angle grinder injuries and can only imagine what the damage a tooted blade can do to a person .

Its only a bit of an extension here to see the potential for a few non thinkers to go this route on ferrous metal.The same warning applies to those who would believe it is a great idea to fit a saw blade to a friction cutting saw.

The design aspects of such friction saw frames are don't lend themselves well to most saw blades with tool rake angles and blade speed designed for an entirely different material.

The potential outcome is not worth the risk.
Please take care gents.

Ozwelder

 

[Tin Falcon]

There Are a number of circular saws designed and marketed for metal cutting. Harbor freight has one on sale for $ 90. I am tempted.

Industry has used carbide on steel for years so why not in the home shop.

When an incorrect saw tooth angle is fitted the saw blades can kick badly.

Agreed make sure you are using the correct blade for the material you are cutting. Read manufacturers manual carefully.

I have been a metal fabrication tradesman for nearly fifty years and seen my fair share of angle grinder injuries and can only imagine what the damage a toothed blade can do to a person .

Kickback is dangerous never put yourself in line with a saw blade or grinding wheel. When using an abrasive grinder or wheel direct the sparks in a safe direction.


That being said I see no reason one can not cut metal safely .

1) use the right blade for the job.
2) run at the correct speed. for the material
3) always wear eye protection .
4) understand how to prevent kickback and take precautions
5)do not put yourself in the line of fire.

Tin

 

[kiwi2]

Thanks for the feedback. I think one of the advantages claimed for the pair of counter-rotating blades is that they are supposed to eliminate kickback. They aren't too expensive so I might get one for the aluminium plate I've got.
One of the other hazards is the swarf. I used a nibbler on some sheet brass and it was vicious stuff. Each piece was the shape of a crescent moon and really sharp. They stuck to my clothes and shoes and ended up in the house. I ended up spending a couple of hours vacuuming out the workshop to get rid of it all. The aluminium swarf which resulted from using the skilsaw (which did kick back) wasn't quite so bad but went flying in all directions necessitating another cleanup of the workshop.

 

[retailer]

I have one and it cut through a piece of 12mm x 150mm Al plate like it was nothing, no kickback, I would however take all usual precautions, clamp the work down, safety specs, gloves etc you know the drill.

 

[kiwi2]

Thanks Retailer. I'll give it a go.

Alan.

 

[Tin Falcon]

Keep in mind with the counter rotating saws. two blades to buy. and IIRC the y cut fast but leave a bit of a rough finish.
Tin

 

[Neil K]

At one of the big-box lumber yards last weekend, I did see that saw with the counter-rotating blades. The description said it could cut darned near everything a home metal worker would encounter. It's a whole lot cheaper than one of those cold-cutting saws too. I was sorely tempted but didn't buy one until I find out more about the machine.

Tin...have you seen one of them in action??

Neil

 

[kiwi2]

I bought one of the saws this morning. There were several models available and I got the cheapest which was NZ$129 which is a bit over US$100. I asked the guy at the counter if it would be OK for steel plate and he said no. As far as steel goes it can be used for corrugated roofing iron but not for steel plate. He said it would be fine for aluminium plate. I used it to cut of a piece of 5/8" aluminium plate and it worked fine. The saw came with 10 sticks of solid lubricant which could be fed into the blades using an applicator built into the saw. I connected a vacuum cleaner to the port on the saw but I only collected about 25% of the swarf so I still had a bit of cleaning up to do afterwards. I don't think I'll bother with the vacuum next time.
I did get a bit of kickback but I think that was mainly because I clamped the plate using a G clamp which stuck up and which I managed to run into with the saw which then skewed a bit to one side. This resulted in unequal forces on the two blades. The cut finish was pretty smooth - it would have been even better if I hadn't run into the clamp.
Hope this is useful for anyone else looking to get one of these.

Regards,
Alan

 

[Tinkerer58]

I have one also and only used it on wood so far, the box does say it will cut steel plate, copper pipe, and various other materials. If you have been told not to cut sheet metal by the store owner I would be very concerned. Her in Australia we have very strict laws regarding false information and advertising. I am now willing to give it a go using every caution and if the safety results are detrimental I will certainly report the finding to the appropriate authorities. I can just imagine some young fella or a home handyman or woman with no techinical expertise taking for granted as true claims written on a box, the result could be horendous. I think it is up to us who do have some technical expertise between us to make the general public and authorities aware of the potential dangers. The importer or manufacturers just want to sell product. The other problem is that the manual is written in China and safety warning are very light on, as like I have previously mentioned on hairdryers (do not use in the shower LOL).

 

[Ozwelder]

Sorry,I failed to make my post clear about the saw blade application.
The original made reference to using a Skilsaw ( circular saw) fitted with a tungsten blade.
I was merely attempting to point out that this blade may have cut aluminium sheet , but that success did not necessarily translate to cutting other metallic materials with the same single, circular saw blade.
There are a number of variables,including tooth angle, tooth set set angle and depth of gullet which means the saw blade used on one material may not be likely suited to others.
Its when the wrong tool is used for the work that the potential for injury increases.
Unfortunately some people may not always have the correct tool for the application or even the experience to recognise a sometimes potentially hazardous situation.

The twin counter rotating blades are an advance in safety but finish can be iffy.

Work safe blokes
Ozwelder

 

[chrsbrbnk]

I've got one of the dual blade saws works great would recommend wearing long pants and shoes when you run it along with eye and ear protection it throws hot chips out and sandles and shorts were pretty intense

 

[Tinkerer58]

LOL yeah chrsbrbnk you don't want hot chips mixing with your chips when wearing shorts LMAO

 

[Engineeringtech]

I don't own one of those saws, but I'm pretty sure I've seen videos in which they cut THIN galvanized steel sheet metal. As long as the material was thin, and the feed rate slow, I think it would be no different than operating a power nibbler.

I've cut a lot of aluminum extrusion on table saws with a metal cutting blade. But steel PLATE is a different animal. For one, it has a much higher tensile strength. I would want to be sure I had at least 2 teeth in the thickness of the material, which is the recommendation for bandsaw cutting. And use a slow feed rate. Otherwise you could break the teeth right off. I don't know if fine pitch blades are available for these counter-rotating saws.

 

[kiwi2]

You can get diamond saw blades for them. I suspect you could cut steel plate with them if you directed a stream of water onto the cut. I've seen diamond saws used to cut through concrete block walls and the cope with the reinforcing steel OK. Mind you, you'd need to use an isolating transformer with all that water flying around.

 

[Tinkerer58]

Water & power tools??

 

[Engineeringtech]

Water & power tools??

Believe me, when I started spraying a water & soluble oil mix on the lathe, mill and drill press, I questioned my sanity! I didn't know if I was going to short everything out, or rust our machines. Hand tools though are a another matter. I'm not sure I want a tight grip on a 120Vac hand saw when an electrolyte is being sprayed on it.

G'day to you too!

P.S. What is in that "bloody shed"?

 

[chrsbrbnk]

Mine was pretty happy cutting 1/8 steel

 

[Tinkerer58]

@ engineeringtech-- only 120Vac, LOL we have 240V here. The worst shock I ever got when I was in the electronics industry, 20,000V arc straight into the tip of my finger, burnt a hole about 3/4" deep, that bloody hurt!!!! In winter the tip of my finger still goes numb after 30 years and I can't feel anything with it. Also had a hot soldering iron fall of the bench, first reaction??- catch it and grab tight , that hurt too.

 

[Swifty]

Saw one of those duel blade saws in the local Target department store today, they had a picture of it cutting through some rebar, looked as though it was at least 5/8" thick. Still would not be interested in cutting any steel though.

Paul.