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

Larry, good old KMS andPrincess have be keeping me happy for years..

 

Absolutely, me too. The tools they sell are for the most part very suitable for anything I need.

 

How many cuts you planning,
on thin wall 4”, myself,I would be making some accurate sheet metal templates ,transferring them to the square section then using a 5” slitting disc , going for it.
Of course, depends on the quantity but you would end up with what you want, not much expense and that did it myself warm fuzzy feeling.
Going by your previous posts you are a man that is a doer so to speak.
Imho.

 

Thin wall 4" tubing is going to be a problem. Most inexpensive cutting methods can't clamp 4" tubing tight enough to keep it from moving. Clamping round tubing is worst then clamping square tubing, but 4" square isn't easy either. Then you add thin wall and it makes it even worse, now you have to deal with not crushing the tubing trying to keep it tight enough to not move as you try to make precision and repeatable cuts.

The next issue is setting up the material your cutting. To get straight, precise, repeatable cuts, the material needs to be supported on both ends as well as on both sides of the cut.

Farm the cuts out to someplace that has a large enough horizontal band saw that can handle the material you want cut. Properly set up, they can probable cut several bars at one time, it may not cost as much as you think. I would deeply consider having the cuts made at the same location you are buying your material from, they probably have the capacity to make good cuts there. Gene

 

The cold carbide saw i post earlier says max rpm 1450

 

It is square tubing.

 

Don't over think it. Regardless of how accurate the cuts are , you'll probably prep the cuts for welding ,if you take the time to build an accurate jig/ fixture , the cuts can be dressed & accommodations / corrections made for accuracy !

 

i didn't read the whole thread, but a metal supplier here local uses a chop saw with some kind of diamond blade. they like it. i myself use my or the companies band saw, but we keep them tuned so they cut straight. other wise i use a torch.

 

I went through this some years back, tired one of the Dewalt carbide blade saws. I didn't like the clamp.
I ended up buying a Kama band saw and love it.
https://kamabandsaw.com/

 

There are (at least) two things that chop saws do that are problematic. Where the wheel contacts the metal seems to make a difference. If it is contacting in the center of a flat surface, they seem to stop cutting and just generate heat into the metal sometimes. Thats when things stop cutting true. If you relocate the part so the wheel is near the edge and work your way across a wider surface, they seem to do fine.
The second thing is the setup. The little angle plate is pretty good for shorter things, but when you start putting a long piece in place, its harder to be consistant.

I would bolt the chopsaw down and make some stops that hit the long end of the part. Clamp or tack something in place so the long end always hits it. A good setup usually insures consistancy.

You might try laying them out with dykem blue and cutting them with a handheld bandsaw.

 

The old deep cut Milwaukee hand held band saw I have will give very good
results in 4 inch thin wall tubing. Slow and careful saw manipulation is the key.
Also clear easy to follow lines that dont rub out at inopportune moments.
My saw is really old and heavy. I have used newer models that are much lighter
and easier to control which results in better accuracy.

 

On saw blades, the thinner the material, the higher the tooth count per inch needs to be. 1/8" wall thickness should have 18 teeth per inch, less then 1/8" wall thickness should have a 24 teeth per inch blade. If the thickness of the material is smaller then the distance between the twwth on the blade, the material will break the blade teeth off pretty quickly.

Also, forcing the blade through the material will give you a crooked cut, and wear out the blade faster. Gene

 

I use a chop saw with pretty good straight cuts results except with heavy bar stock. The trick is finding the right disk if you use disk that are low wear and you have to use alot of pressure you will get a crooked cut. If the disk does not wear and glazes it will stop cutting. You want a disk that wears so it will have a fresh cutting edge.

 

I may just experiment with a few different blades. I hate to have to tool up for one job. I know that I will have the tool forever, but this particular job is gonna run into some cash, so keeping the overhead low will help.

 

When I was in High school, the Ag shop had a ancient, huge DeWalt radial arm saw. It was probably Govt surplus, maybe from the military. The teacher had multiple blades for it, wood and metal cutting. This thing would cut through angle and box tubing just like it was cutting pine lumber. We made steel mailbox posts for the FFA to sell, set up a jig to cut the angle, flop down some steel and cut, every piece came out identical. I don't remember how many teeth the blade had, but that thing was huge, maybe 16"? And powerful too, you had to really watch when cutting lumber, it was known to snatch it and throw it across the shop a few times!

I know something like that would be overkill, even if you could find one, but it seems to me a normal radial arm saw with a toothed metal cutting blade might be worth looking into. You could cut several pieces at a time making all the same length.

 

I'm with chevyfordman from page 1. I also have a Ellis band saw that has the pivoting head to do miter cuts. With the proper blade (bi-metal for good life), the guides on both sides of the cut set as close as practical to the material to keep the cut straight vertically, and a slow feed rate the cuts are very accurate. I used it in my fabrication business for years and cut things from 4" X 4" X .250" mild steel square tube down to 1/2" X .062" stainless steel with great fit-up.

Before the Ellis saw when I was just starting my business, I used a "hobby shop" band saw like you see at HF and other places. Set-up and firm clamping to cut accurately were a bit of a challenge, but it too did the job.

As mentioned before, tooth count is important using a band saw. I always tried to use a blade that had a fine enough tooth count that the distance between teeth was closer together than the thickness of the metal. ie: 16 Ga (.062") use 18+ teeth per inch blade.

Depending on the number of cuts you need to make, is there a fabrication shop nearby that would have a patient enough operator to make the cuts you need accurately?

Also...FWIW....I really dislike carbide disc (14"?) chop saws. Cut accuracy and the mess is terrible, IMHO.

Lynn