cold saw woes

[Tony]

I'm hoping someone can point out what I'm doing wrong with my
cold saw.

I only use it to cut solid stock.
There's always plenty of coolant in the saw and i keep it rich, just in case
There are 2 speeds, I almost always use the slow one. Am in no rush.
Moderate pressure. I don't push like crazy or let the blade skate.
The blades are "premium" brand, HSS.
My material is almost always "good" (mystery metal to a min on this saw).

It cuts beautifully. Looks like the faces have been machined.

Thing is my blade life is hit/miss. Costs me $20 a sharpening. $80 a
blade.

Put a new blade in this morning, was cutting off some 2.75" hex stock.
1040. Made it through 1/2 of my first cut and the thing is dull already.

Should I just scrap this thing and get a bandsaw?

Tony

[Black_Moons]

Can we get some more data?

What RPM are the two speeds at the blade?
What diamiter is the blade?
What TPI or tooth count is the blade?
What color and shape are the chips?
How many inchs per minute of 2.75" diamiter steel will this saw cut through with 'moderate pressure'?

[legendboy]

we have to use carbide tipped blades on our cold cut saw at work

this is for cutting mostly mild steel with some stainless

[Ries]

thats weird.
I run my cold saw on the slow speed, which for me is about 45 rpm.

And I find, cutting hot rolled or cold rolled, I go about a year between resharpenings.

I buy my blades from either Doringer or Ken Bergman, the Haberle rep. And they last forever. Unless I physically break one, I find a blade can last ten years or more easily.

Are you using the proper tooth count for what you are cutting?

you sure it wasnt stainless? mine doesnt like stainless, they say you need a special grind, and a slower speed- 25 rpm or so.

[oldtiffie]

The people at my metal etc. supplier really "lay into" their HSS cold saw and even if there are a few teeth missing the saw keeps going.

[PaulT]

Tony, its possible you got a bad blade.

The way things are going with industrial suppliers these days it could be that the blade manufacturing got pushed overseas and the quality went down the toilet.

This has happened to tons of US brands that used to supply very quality products (Jacob chucks, Nicholson files, . . .) and now just sell pure junk.

If your feeds and speeds seem correct, I'd try a different blade brand, perhaps one the one suggested by the other posters.

Paul T.

https://www.power-t.com

[winchman]

I tend to put a lot of pressure on the handle on our Doringer, especially when a lot of teeth are in contact with the work .

I can tell when someone has used it for stainless, because it really kills the blade.

We recently disabled the high speed feature. No matter how many times the students were told not to use it for anything other than aluminum, they insisted on using it for steel. That won't happen any more.

[firbikrhd1]

A metal supplier locally sells only stainless and aluminum and uses cold saws exclusively to cut everything except sheet stock. His cold saws turn between 40 and 60 RPM and use carbide blades. They quickly chew through diameters of either stainless of aluminum up to 12" using hand pressure without even breathing hard every day. My guess is that your blade is the culprit.

[The Artful Bodger]

My cold saw chomps through thick wall hollow sections (rectangular and tube) but is not much quicker than my band saw on thick section.

I assume it is all in the tooth count to thickness ratio.

[Tony]

Just went out to the garage and took some measurements.
The low speed doesn't even register on my tach .. barely moves.. if
I had to guess its less than 50 rpm on the low speed. High speed
looks to be about 125 or so. tach is 0-3500 mechanical engine tach..
all I got.

Blade is 11.5" with 5TPI .. 0.1" thick.

The chips are small and bright. 0.1" wide curled into little cylinders.

its a 'compound' grind (not sure what to call it) every other tooth
is beveled on both sides so I have a flat tooth, then what looks
like an 80 degree tooth, then flat, etc.

On a good run (try to answer Moon's question) it probably takes me
a minute to get through 2" round steel. thats a guess.

I've only had this saw about a year.. in that time I've probably changed
blades 4-5 times. Its getting expensive.

Are the carbide tipped blades special for cold saws? i have a 10" carbide
tipped fine cut "construction" (dewalt) blade thats meant for a table saw.
I don't have a table saw that it fits. have had the thing for years and will
prob never use it. Dangerous move to fit it to the cold saw?

Tony

[Doozer]

Pink elephant in the room.

--Doozer

[Tony]

not quite sure what that means, doozer.

my saw is an alcoholic?

[Ries]

Although the internet is an extremely good place to find cute cat pictures, political opinions, and catchy songs, I think you need to call a real cold saw blade supplier, and "talk" to them, as opposed to typing.

Yes, actually talk on the phone.

I find that this antiquated technique still works, believe it or not, and talking to ONE saw blade expert is actually better than reading random comments from several hundred people who dont even own a cold saw.

I recommend you call up these guys-

http://www.coldsawblade.com/contact.html

They have been really helpful to a bunch of people who own cold saws.

You will need to tell them the make and model of your saw, or at the very least the actual rpm you are using- and the size, and the info on your current blade.

There is no reason that you should have gone thru 4 or 5 blades in a year, unless you are running the saw full time 3 shifts, 24/7.

Something is wrong.

And talking to somebody who really knows about these saws and blades should help you figure out what it is.
My guess is you should get a year or more out of a blade sharpening, in a typical home shop situation.

Maybe your blade is crap, maybe you are running the wrong blade, maybe the speed is not what you think- I dunno.

[Tony]

Well, Ries, I want to thank you very much, I did call Quinn Saw and spoke
with a fella named Troy -- extremely knowledgeable / helpful.

Turns out my tooth count is too high for what I usually cut (greater than
1" solid) -- and killing my saws prematurely.

He gave me an excellent price on both resharpening and retoothing to
a coarser pattern.

What I was surprised to hear is that the rule of thumb, according to Troy,
is 4-6 teeth in the cut.

Cutting 2 3/4" hex means very coarse saw.
I had 15 teeth in there.

Thanks again.

Tony

[Black_Moons]

Turns out my tooth count is too high for what I usually cut (greater than
1" solid) -- and killing my saws prematurely.

He gave me an excellent price on both resharpening and retoothing to
a coarser pattern.

What I was surprised to hear is that the rule of thumb, according to Troy,
is 4-6 teeth in the cut.

Cutting 2 3/4" hex means very coarse saw.
I had 15 teeth in there.

Thanks again.

Tony

Yes, with high tooth counts and large work you need insane pressure to have enough per tooth pressure to cut properly. Chips sound about right.

Re toothing a saw blade? Wow. I wonder if he just makes it smaller (Solid HSS?) or lobs off every other tooth or what?

As far as rule of thumb, Yea, thats the 'ideal' tooth count, you do NOT want to ever go lower then 3 teeth in the cut however as it will quickly ruin the blade.

I don't even wanna think about when I cut 2" round in my bandsaw with the 10~14 TPI variable pitch blade and only driping oil into the cut.