Technical Cold saw blades vs Chopsaw blades- metal fabricators chime in

I am planning to do quite a bit of fabrication in the near future using a large dimension square tubing. It will have a lot of 45* angles. The problem I have is when I use my chopsaw, I get inconsistent angles, due to the flexing of the blade.

I realize a cold saw is a different animal and lubricated etc. , but could a guy use a cold saw blade in a chop saw or are the rpms too high etc? I don't want a grenade.

It would be a one project use, then back to the standard blade.

Or do you guys have any ideas short of buying a horizontal bandsaw?
I could farm out the cutting if I have to, but I would rather not.

Does something like this maintain it's angle?
https://www.dewalt.com/products/acc...-gauge-ferrous-metal-cutting--1-arbor/dwa7747

 

I use a pretty cheap Rockwell horizontal bandsaw that cuts deadly accurate. I feel the infield/outfield table has more to do with accuracy than the saw itself. Rig something creative and any of the saws will work. never use a cold cut blade in an abrasive saw. You will trash the blade instantly, (too fast) and it is dangerous as well as the carbide is generally not rated foir that much RPM. Ther cold cut is definitly the cleanist cuts of them all.

 

This is what i have, i love it. the blades are about 70-$80, not sure if they work in other saws tho.


Evolution Power Tools R355CPS 14 inch Chop Saw with Multi Purpose Cutting - Cuts Through Metal, Plastic, Wood & More - Inch Multi Purpose Blade

 

I have a regular chop saw, Dewalt I think. 14" blades. The problem with the abrasive blades are they flex. If you are looking for precise cuts, they get exaggerated on a 4" piece of tubing and you end up with 3/8" of difference. The pieces I am building are OT but just envision a giant X with a piece running ride down through the middle. They need to be accurate and repeatable.

 

Absolutely can’t use a cold cut blade in an abrasive cut saw.
DANGER WILL ROBINSON
The cold saw blade is not rated for the abrasive saws RPM.

Personally I love the cold saws clean cutting precision.

Most other saws including band saws will do less precision cuts and that can be especially true for band saws when you try to get the cutting speed too high.

Just like any other cold cutting, drilling or machining type of equipment the tools or blades will last longer if the cuts are cooled and lubricated by some type of coolant.
Water soluble oil that milky white stuff works great.

Cold cut saws that run dry will be limited to the number of cuts but the ones with coolant can last up to 3-4 times longer.

I bought a little 7” cold cut saw that is perfect for light duty work on small tubing etc.
Princess Auto stopped selling them but blades are still available.

For more serious work I’ve been tempted to pick up something like this.
A 12” or 14” coolant equipped cold cut saw.


DETAILS
For tight tolerances and clean finishes when cutting metal, a cold cut saw is your best bet. This heavy-duty 14" model from Magnum Industrial delivers precise cuts in a variety of ferrous metal cutting applications—angle stock, pipes, extrusions and more. It features variable-speed cutting with a digital speed display, a high-capacity coolant tank, and quick-clamping vise that makes loading and unloading more efficient.

• Powerful 3 HP motor cuts a variety of ferrous metal—steel, cast iron and more
• HSS blade (sold separately) delivers clean, accurate results
• Variable speed control with digital display adds consistency for repeatable results
• Quick-clamp vise makes it easy to load and unload material
• Control handle with safety trigger switch provides comfortable, ergonomic workflow
• Coolant pump with 5 litre tank limits downtime due to refilling
• Water channel is specially designed for efficient cooling and lubricating
• Shockproof control panel stands up to workplace wear and tear
• Overload protection and magnetic starter

Specifications:
Motor*: 3 HP, 220V, 9.6 Amps, 1,720 rpm
Cutting capacity at 90º (solid round stock): 3.5" (85 mm) diameter
Cutting capacity at 90º (tubing): 4.7" (120 mm) diameter
Cutting capacity at 90º (square): 4" x 4" (100 mm x 100 mm)
Cutting capacity at 90º (rectangular): 6.3" x 3.5" (160 mm x 85 mm)
Cutting capacity at 45º (solid round stock): 3" (75 mm) diameter
Cutting capacity at 45º (tubing): 4" (100 mm) diameter
Cutting capacity at 45º (square): 3.5" x 3.5" (85 mm x 85 mm)
Cutting capacity at 45º (rectangular): 3.5" x 2.8" (85 mm x 70 mm)
Blade size: 14" (350 mm) x 0.1" (2.5 mm)
Arbor: 1.25" (32 mm)
Bevel capacity: 0 to 45 degrees
Spindle speed: 24 to 120 rpm
Maximum vise opening: 6-11/16" (170 mm)
Coolant tank capacity: 5 litres
Coolant pump motor: 1/8 hp
Dimensions (l x w x h): 47" x 39" x 67.7"
Weight: 552 lbs (250 kg)

*This unit requires a 220 volt single phase power supply. It converts to three phase with an onboard digital inverter.

 

The RPM of my cold saw is something like 60.

You want a mad-of-metal chop saw blade. I used to run one years ago in my Milwaukee chop saw. I think it had 80-teeth. I got about 100-120 cuts per blade. It was carbide dust-free. Hate that dust.

As with any hand-pushed mechanism, you need to let the blade do the work. Don't force it, and make sure you don't accidentally bounce the blade off of the work piece. You can break teeth off.

If pushed too hard, it could still be deflected, but then again, so can my cold saw.

 

Ultimately I would like to invest in one of the good ones, but it is a ways down in the priority list.

 

Any idea on the name of the blade?

 

An expensive 'consumable' for a one time project sums it all to me. I'd farm out the cutting. Just better time/money management. It's like buying a Bridgeport just to clean up the keyway on a spindle of a car you're getting rid of.

 

I like my Fein Slugger so far. Nice cool, straight, almost burr free cuts. Best to keep it under 3/16 wall for cuts in anything bigger than 3" tube. At some point you have too much surface contact and can't make it pull a chip anymore. Then it just heats up and stops cutting. How big of tube will you be working with? I have heard the 12" Makita saws are nice and work pretty well up to their rated size. I think the smaller blade increases rigidity and makes for less surface contact at any given point in the cut.

Whatever you do, once you get over the sticker shock you will be happy with your new tool / toy once you start to actually use it.

 

The tubing is going to be a thin walled 4”. I’m not sure on what thicknesses are available. I may farm it out as long as they are as accurate as I want it.

It’s not a precision deal, but it is for something that is going to be in my house for a long time. It’s for mama’s dining room. We had some tornado damage a while back that ruined some of our overpriced import furniture. I am making the next set in America from real steel and real trees.

 

Always wanted to get one when I saw them on a TV show years back. Wasn’t so much for precision cuts, but for the lack of debris and sparks flying around.
I put my chop saws on stands with wheels, have to roll it out of the shop, use it, bring them back in. Been a PIA for a long time.

 

I love my chop saw... so much so that I sold my Porta-band after I figured out how to use the chop saw. With that said, a cold-cut saw is more accurate but also costs a whole bunch more. But what I found out is set-up, operator skill and blade choice make a big difference when using a chop saw.

One, make sure the material clamp is square to the blade (or whatever angle you're after), and the blade is square to clamp table. Most saws can be adjusted, being off even a small amount will result in angled cuts. Make sure the saw pivot axis is square to the blade, if it's off any you'll get angled cuts. If cutting long pieces, make sure you support the end away from blade. Making sure the support is EXACTLY the same height as the saw table makes a difference, so much so that I purpose-built one out of metal for just that. Having a flat surface to set-up on makes a difference also.

Two, let the blade do the work. Too much pressure will affect cut accuracy, too little shortens blade life. This can be a tough one and not all blades cut the same. You'll have to experiment a bit here to find the best results. Which bring us to...

Three, blade choice. I was surprised at how much difference this made. I tried multiple brands from the box stores and industrial suppliers trying to find a blade that would cut straight (and not wear out quickly), some were better than others. Now don't scoff, but I was in HF one day and they had chop saw blades on sale. A five-pack was about the same price as one name-brand anywhere else, so I figured it was worth a shot. These were the answer! They lasted longer and cut straighter than any other ones I found. Didn't cut as fast as they were thicker than the name brands but that was one of the big reasons they worked better. Next time they were on sale I bought 30 of them, I'm about 1/2 way through my stash after all the years. Now, given how HF changes suppliers all the time I doubt if the ones I bought are still the same, but do check blade thickness of whatever you buy. You may be out of luck at HF as current offerings are 3/32" thick, they've discontinued the 1/8" thick ones. Look for the thicker blades.

You can get a dead-accurate cut with a chop saw if it's set up right, although probably not with an abrasive blade. Years ago when I was still working we had a custom light fixture order for a bank lobby with odd-length fixtures. They screwed the order up and we didn't have time to re-order, so I modified the ones we got. The housings were extruded aluminum so I switched to a 80 tooth carbide blade on the saw to cut them. These bolted end-to-end, any miss here and you'd have 'kinks' or gaps showing at the joints. They came out perfect...

 

Depends on how you look at it. About 7 years ago we had a flood in our house and ruined the wood laminate floor. We opted to remove it ourselves. Insurance paid us $500 to remove it. Yes, I spent $200 on a rotary hammer drill with a scraper blade and probably lost money with my time spent. Fast forward to today and we are getting ready to renovate the house and I need that very tool for some of the demo work. Now it starts paying dividends.

 

Mine was a DeWalt.

I am looking, and I am not seeing it now. Looks like just 66-teeth, and 90-teeth now:
66T: https://www.dewalt.com/products/acc...-gauge-ferrous-metal-cutting--1-arbor/dwa7747

90T: https://www.dewalt.com/products/acc...t-gauge-ferrous-metal-cutting-1-arbor/dwa7745

Either that, or my memory is failing. I know it was not 66T.

 

If you're using round tube, a well-set-up chop saw will give a very accurate cut on big-bore thin-wall EMT. On any job I did after I figured all this out, that was my method of cutting all larger conduit if I had more than just a few cuts to do. Far faster/easier than using a Porta-band which was the 'normal' choice. Just had to clean off the burrs after cutting was all, a few passes with a file took care of that. No reason it couldn't do the same on square tube. Cold cut saws don't do well with thin-walled material from what I've seen.

 

For the furniture project you might check into renting the saw you think might do best. Some times you have to pay for a blade but if you are all lined out and have your cuts planned out you ought to be able to do all the cutting in a short time frame.
I've got a Black and Decker industrial chop saw that I have had for 30 years and a horizontal band saw that I picked up for cheaps and put new guide bearings in but wouldn't be wanting to do precise cuts to make house furniture with either.

 

For a one time use, just use a hacksaw. Check out Alan Millyard on Youtube. What that man can do with a hacksaw is amazing.

 

Not a good solution but try different brand of wheels in you chop saw also try less pressure on the wheel. Different wheels cut so differently, I have had cut like a knife in butter and some that cut like c—-.

 

We found a Porter Cable cold saw at an auction; does a good job. No sparks or dust; but does make a mess. The chop saw is just used for exhaust tube now.

Are you welding the 45 degree joints? If you are, maybe mark the tube all around and cut each side individually with an angle grinder.

 

If you don’t want to break the bank wen makes a pretty good one for about 250 bucks get them at Lowe’s

 

I've got a 12 inch Makita cold saw and love it! Not just accurate cuts but no grinder smoke and stink from the abrasive blades. The cuts are a little safer too , they don't have that little blue razor blade burr that always slices you open. With a quality blade and careful cutting it should take a while before you need to replace the blade.

 

Another thought (as mentioned before) is a band saw, not much mess. I picked up an old Perkins some years back that’s I guess would be a reciprocating saw. Uses a 10 inch long blade, about an inch or so thick. It’s slow, but makes good cuts. I’ll post a pic of it for consideration.

 

The best piece of advice anybody could give you is to purchase a GOOD QUALITY BLADE, the more expensive saws are made for daily industrial use, but a good DIY or Trade rated tool set up and used carefully with a good blade will get you good results.

 

From doing some research, it seems that cold-cut saws don't work all that well on steel thinner than 1/8". Kind of like trying to saw sheetmetal with a low-tooth-count-per-inch hacksaw blade They'll do the softer non-ferrous metals. Where they shine is on thick steel.

I've got a 80-tooth carbide blade for my chop saw, works great on aluminum. The saw turns too fast for steel use.

 

If you have the space and can afford it, one of these is my choice. The way the head swivels and the accuracy have had it my favorite. I bought a huge amount of Makita blades for my 14" cutoff saw. I found them to be terrible at cutting straight. https://www.ellissaw.com/mitre-band-saw-overview/

 

I am lazy. That ain’t happening.

 

I have an Ellis miter saw also and though they are expensive, I ended up using it for so many more projects than originally bought for. They are a non lubricated saw ( dry ) and they work superbly so look for one of these one day, you will never regret it except it has a big foot print.

 

If you have a finite number of cuts maybe you could pay someone to cut them for you on a larger horizontal band saw. If you were close to KC you could use mine. Or if you want to drive...
For any of the options I agree that, with the weight of the stock involved, some form of out feed and in feed support would help the saw hold the angle. The clamps are pretty short on any saw so with that weight inaccuracies are bound to creep in.
JMO,
D