Large Diameter Cold Saw vs Band Saw Cut Speeds

I'm looking at purchasing an semi/automatic coldsaw capable of cutting up to 9" round.

Based on solid round 4140 (28-32 RH) material and a 29.5 diameter blade (carbide), can anyone tell me what the cut speeds might be like compared to a new bandsaw.

I've heard claims thrown around that the cold saw will cut 3 times as fast but haven't really been able to find anything to support the claims.

Thanks in advance for any feedback!

Good question I would be interested in the answer also.

Size of kerf and rigidity of machine will tell you speed of cut. Coldsaw will lose in kerf width. And you’re wasting spendy material. In the past when a close friend was the manager of Marmon near RRCC off Route 90, I’d just get stuff like you mention pre-cut to my needs. Not sure if they are still doing this or if I got a special. Prob worth a call.

Failing that the old man at Wallace is the best guy I know locally for questions like this.

L7

On edit: GoogleFu shows Marmon moved- near Headingly now, and seems to now do mostly tube….

Here find the band saw cut speeds.
Band Saw Blade Speed And Feed Chart

I have owned both a cold saw and a big bandsaw for quite some time. My coldsaw is a measly 350mm blade, which means it will cut about 3" material- versus the gigantic 1500mm or larger blade you would need- but its been my experience that for most metals, a bandsaw is much more efficient for cutting solid 9" rounds.
I have seen coldsaws with 30" and larger blade diameters, but they are usually track saws for cutting large, thick plate.
When I lived in California, I used to use these guys for precision plate cutting, and they have a cold saw capable of cutting 6" plate- and its a 46hp, 14 ton machine. The reason they use a circular blade for this is to hold precision on long cuts. Precision Sawing Services for Metal - TCI Precision Metals

If I was cutting 9" round, I would use a bandsaw. As mentioned above, kerf is much thinner, and with a hefty horizontal bandsaw, you will get almost the same degree of accuracy as with a gigantic cold saw, at a lower price, with lower priced blades, and less heat affected zone. When a colds saw, even one with lots of coolant and a very slow speed, is cutting thru a big solid round, you get more heat build up than cutting the same material with a bandsaw. The bandsaw blade gets better coolant coverage, stays cooler, and keeps the material cooler as well, in my experience.
With an 1 1/2 or 2" wide bandsaw blade, you will get accuracy.
A really big cold saw like that is rare, expensive (almost always german, great quality, but pricey) and big and heavy and requiring lots of power.

Near me, there is an incredible sawing house, which mostly services Boeing and similar aerospace companies. They have probably 30 saws, including full auto slabbing saws where I have seen them cutting 1/2" thick slices off of 12" x 12" x 96" titanium bars the long way.
It is pretty telling to me that they have almost no cold saws- instead, their huge shop is full of Amada bandsaws, many of which are quarter million dollar machines- so they have the needs, the budget, and the experience to buy any saw they want to cut some of the most exotic stuff to very precise dimensions, and they consistently choose bandsaws.

Sunbelt Turret steel is local to me. They are one of the bigger suppliers of large diameter steel barstock. They use bandsaws with carbide toothed blades to get the best value overall. I recall they made the switch to the carbide blades about 6 or 7 years ago. I think the cut speed went up by 50% which more than makes up for the times their employees crash the expensive blades.

A cold saw works best with 3 teeth in the cut and every one of them taking a chip a thousandth of an inch thick, or so. Babying the saw is no good. So to saw a 9" round requires a tooth every 3 inches. That is 'bumpy' to get started.

Using a blade with teeth too small for the cut will result in the gullet getting filled up, and breaking out a tooth. A 9" long chip takes a big gullet.

Thanks all for the quick replies.

Lucky7, this is for one of my locations out west and we already have quotes on a few machines but I haven't been able to find anything that speaks to cutting feed rates on larger diameter bar for cold saws. Most of what we do is actually heavy wall pipe that gets gun drilled prior to cutting.

You note about vibration is important as it seems advancements have been made in this area in recent years on both band and cold saws.
We were also considering a large Kasto production bandsaw that would have more bundle cutting capability and should also be a consideration given we could likely shuttle more lengths in for each cut.

Thanks for the lead Garwood! I have a contact for one of the Ops Managers at Sunbelt and will be calling him for his thoughts.

Cheers

I just spoke to my contact at Sunbelt and he could only comment on cut feed rates up to 6" solid round but indicated the cold saw will in fact cut that same piece 3-4 times faster than their bandsaws.

The kerf width also doesn't appear to be a huge difference with BS blade typically around an 1/8" and CS blades at 3/16". A concern if your cutting 1" long pieces all day but not so much for our needs at 3-15" long pieces.

Don't forget that, if you don't already have a guy, you will need a shop that can service a large diameter blade. I'm talking about guys that can sharpen, repair and tension blades that size. Tension won't be as critical with the low RPM but still needs to be addressed.

I recently started up (2) Amada Hyper Saw HPSAW310 saws at a steel supply house. Now those bandsaws will compete with a coldsaw! Carbide tipped bandsaw blades and band speeds close to 1000FPM.
We have a video of it running at the Amada website. They will show what the state of the art in bandsawing is.

https://youtu.be/BOSHOswRKY8

That's 8" diameter 1045 steel in 30 seconds!

BillWojo

Pipe may be more suited to a cold saw than solid, which is what I was thinking when you said 9" round.
The additional rigidity of a solid blade, versus a bandsaw, is sometimes an advantage with the interrupted cuts on pipe. I did a little work a few years ago with a friend of mine who builds breweries, and he is always working with stainless pipe, ranging up to the size range you are talking about.
In that industry, they do, indeed, use cold saws- the market for thinner wall SS, for chemical and food service piping, seems to be dominated by Georg Fisher, of Switzerland, since about 1960.
They make cold saws with chucks, to hold the material very firmly right next to the blade, which is really great for thin wall precision cutting. And they use a smaller blade size, and rotate the saw around the pipe while cutting, so the blade doesnt have to be big enough to cut the whole pipe in one pass, just enough to cut the wall thickness.
I dont know the wall thickness of your gun drilled pipe, it could be thick enough that the vibration is not as big an issue, but for large diameter, thin wall pipes, the combination of a cold saw and a chuck has long been considered the best way.

The above 3 tooth rule would give you a very different tooth count, if your actual material being cut is a 3/4" wall, rather than a 9" round.

The Georg Fischer machines may be too small for the work you want to do, but that style of rotating cutting head pipe cutting would, I think, be as fast, if not faster, than a bandsaw.
Not sure who makes big ones. Graebner Reika? Cold Saw Revolutionizes Pipe Cutting for OCTG and Other Industries | Fabricating and Metalworking

9 inch pipe heavy wall is 3.2 effective inch cut. A band saw with a decent normal blade is 7 ipm running conservatively thru that. just over a minute per cut. You can amp that with some operator input and finer tooth blade (5/8) to be 5 ipm thru the front and back wall and 12 ipm for 8 inchs of the cut... still conservative.
NEVER BUNDLE CUT. you should not have that in your vocabulary, forget carbide if you even hear the word. That 7 ipm turns into 2 ipm with three pipes and it only gets worse from there (You can pair stock if you adjust speed to creeping between the parts). There are saws that can bundle cut, dedicated to a specific stock size, with really cool clamping set ups and monitoring, but way beyond the cost of an army of amanas or hyd mechs. Railroad saws mostly. Also nothing ages a saw like bundle cutting.
We have a cold saw similar to Ries, it has a tigerstop which more than makes up for the slower cut on smaller stock.

The Nishijimax cold sawing machines are very good.

Nishijimax - NHC-230AL High Speed Sawing - YouTube

Are you really cutting that many 9" rounds that speed is a pressing issue?

We are scrapping a Pedrazzoli Super Brown 350 semiautomatic cold saw bought new in 2001. Compared to the band saw we had at the time it cut squarer and involved less overall work. However after the band saw got replaced in 2005 by a HEM double column 14-inch band saw, that all changed. The HEMsaw is fully programmable with automatic work feed, and even though it's pretty big everybody will use it in preference to the cold saw no matter the workpiece diameter. When I realized the cold saw had sat for a good while and looked at the cost history of regrinding blades (including shipping) it occurred to me it was taking up space. The HEMsaw will hold .005 squareness in 5" Ø steel, and you can walk away and come back to a hopper full of slugs. It cost around $45K but has been worth every cent. Never going back to a cold saw. Your results may vary.

WCOPS said:

Thanks all for the quick replies.

Lucky7, this is for one of my locations out west and we already have quotes on a few machines but I haven't been able to find anything that speaks to cutting feed rates on larger diameter bar for cold saws. Most of what we do is actually heavy wall pipe that gets gun drilled prior to cutting.

You note about vibration is important as it seems advancements have been made in this area in recent years on both band and cold saws.
We were also considering a large Kasto production bandsaw that would have more bundle cutting capability and should also be a consideration given we could likely shuttle more lengths in for each cut.

Click to expand...

Bandsaw it and sent it up for automatic feed. boom, cycle time doesn't matter if an operator isn't hovering over it. come back and a whole bar is cut. if qty is needed, buy 2 of them.

GregSY said:

Are you really cutting that many 9" rounds that speed is a pressing issue?

Click to expand...

Do you think the steel suppliers just have all those big bars in stock to look at them?

My Cosen auto saw will feed and cut 14" bar. However, my forklift only lifts 3000 lbs and my Cosen runs a 1" blade which doesn't do great past about 8" stock. I would save a bit of money if I sawed 14" bar in house over paying for the cut time, but I can't actually handle the pieces or get the accuracy required.

BT Fabrication said:

Bandsaw it and sent it up for automatic feed. boom, cycle time doesn't matter if an operator isn't hovering over it. come back and a whole bar is cut. if qty is needed, buy 2 of them.

Click to expand...

Have you ever cut big barstock unattended?

What happens to those 150 pound pieces coming off the outfeed table?