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View Full Version : bimetal or carbon steel bandsaw blades?



clutch
12-28-2009, 08:03 PM
Shop is up and running. I don't have a bandsaw yet. My uncle up the road has a 4x6 that works pretty well. I need to buy a blade or two to feel right using it to cut my stock until I have my own saw.

So bimetal or carbon? Most of my cutting will be 1018, 1044, and a small amount of O-1.

Thanks,

Clutch

nheng
12-28-2009, 08:21 PM
I use Starrett bi-metal blades for my old Craftsman horizontal bandsaw and was fortunate at that to find the odd length it uses. The bi-metal performs well on everything from plastics to non-ferrous to alloy steels. The blade is a 12 - 14 variable pitch which helps reduce resonances. Den

terry_g
12-28-2009, 09:07 PM
I purchased a chinese 4x6 bandsaw it came with a carbon steel blade.
The blade dulled very quickly. I replaced it with an inexpensive bimetal blade and have used it a lot and it still cuts like new.
Terry

lazlo
12-28-2009, 09:07 PM
My vote is bi-metal. They last way longer than carbon steel blades.

Ries
12-28-2009, 09:10 PM
bimetal.
10-14 variable pitch.
I like the Lenox Diemaster II blades better than the Starretts.

Black_Moons
12-28-2009, 09:44 PM
Bimetal UNLESS you plan to cut something so nasty bimetal isent worth it... AFAIK that only includes really abrasive/nasty materials like fiberglass, all metals should cut better with a bimetal.

ie, anything that can dull a bimetal in a few cuts your better off going with carbon steel, it won't last longer but it will be cheaper per cut.

Basicly as a HSM your best off with bimetal unless you have some nasty production job to do.

Evan
12-28-2009, 09:54 PM
1 x bimetal = 10 x carbon steel

I don't agree with BM. If it will kill a bimetal blade then it will rip the teeth off a carbon blade in one rev. I've done it.

If you have something that nasty to cut it's time for a diamond grit blade.

scatter cat
12-28-2009, 09:57 PM
Get the speed and feed right and run some sort of coolant on your saw even a carbon steel blade will last quite awhile.

Black_Moons
12-28-2009, 09:57 PM
Evan: then what are carbon blades even for? Im pertty sure theres gotta be something they cut better for the dollar or they would'nt be sold anymore.

Im not saying nasty as in hard steel nasty, im saying nasty as in like fiberglass PCB's. things that would abrasively dull a bimetal blade.

Willy
12-28-2009, 09:59 PM
Go for the cheap carbon blades.
In no time at all you'll be a whiz at changing blades.
Amaze your friends with your lightening fast reflexes as you change blades with your eyes closed!

Seriously though, go for the 10-14tpi variable pitch for general purpose cutting.
I've had really good experience with MK Morse (http://www.mkmorse.com/index.html) brand saw blades, but I think you'll have good results with any of the brand names others have suggested.

Black_Moons
12-28-2009, 10:14 PM
nah the better amazement is when you managed to untwist the blade infront of your friends without decapitating anyone.

And if you screw up, just tell them that was your 'sawing a guy in half trick!'

Boucher
12-28-2009, 10:14 PM
If you intend to use your saw buy good blades. I used a lot of carbon steel blades before I discovered bimetal blades. I still have several carbon steel blades hanging on the wall but when it is time to change blades I reach for the better ones. It is surprising how long a good blade lasts compared to the cheaper ones. Good blades are cheaper in the long run but you can wreck anything. Carbon blades function best as loaners.

mechanicalmagic
12-28-2009, 10:17 PM
The most common answer is Bi-metal.
I choose another path. I use only quality blade stock to make my own blades. The reason is this:
I'm a scrounger, and have a metal rack with all sorts of steel, Al, Brass, several types of tool steel. Many are known alloys, some are not. I have a bunch of stock/drops that are pure blade-dull-ium, not sure where they came from, and I am slowly marking that alloy, as it is discovered. It lathes just fine, but kills blades with 100% certainty. It would drive a stake in my heart to use a new bi-metal blade and discover that I had grabbed a bar of blade-dull-ium.
Another thing, I use TPI's from a 4 skip for thick stock, to 32 for thin stock, depending on the material thickness. Buying blades to cover the range can be rather expensive. As always tooling is often more expensive than the tool itself.

Black_Moons
12-28-2009, 10:22 PM
mechanicalmagic: Ever try to file or hacksaw those 'blade killing' materials? Might be a little easyer test.

Mcgyver
12-28-2009, 10:28 PM
mm's way is probably the best, although i confess to buying bimetal blades and slapping them on. unless you're cranking the speed, what exactly is the advantage of the bimetal blade? hss's advantage over tool steel is maintaining hardness at higher temps.....and temps are a direct function of cutting speed. So long as temps are down so it doesn't draw a temper, tools steel should last as long as hss. Run slowly, tool steel would i think deliver quite a bit more square inches of cut per dollar

Forrest Addy
12-28-2009, 10:36 PM
Bi metal. I've used both on my chicom 7 x 12. My experience is bi-metal costs twice as much but lasts 4 to 6 times longer. Even I can work that math.

Fasttrack
12-28-2009, 10:38 PM
The carbon steel bandsaw blades have the advantage of greater flexibility. These "soft back" blades work really well when you are cutting out strange shapes on a vertical bandsaw, but they still dull much faster than bimetal. They are also cheaper. I went through four carbon steel blades (not counting the chineese one) on my 4X6 before I switched to an "aggressor" bimetal blade. I think it was the cheapest bimetal blade that Enco had and I bought two of them. I've yet to replace the first one and I've cut a lot of spring steel, 4140, cast iron, low and medium carbon steel, leaded steel, etc. I've often pushed the saw beyond it's capacity and yet that blade is still sharp.


My vote is for bimetal!

Mcgyver - Keep in mind that the instantaneous temperature at the tooth can be pretty high, even when the blade is running slowly. Also, bimetal is, I suspect, harder than ordinary steel. For instance, most tool steels harden to a max of about 60 Rockwell C while M2 can be hardened to 65 Rockwell C and Rex 95 or other high cobalt alloys will harden to 69-70 Rockwell C. Of course, their main advantage is increased hot hardness, they are still a little bit harder even at normal temperatures.

edit: Clutch - if you choose bimetal (you should :) ) then you probably only need to buy one blade. Unless you run the saw "balls to the wall", you'll probably decide you need a saw for yourself long before it becomes time to change the blade again.

mechanicalmagic
12-28-2009, 10:40 PM
mechanicalmagic: Ever try to file or hacksaw those 'blade killing' materials? Might be a little easyer test.
Nope,I got so many drops and bars in the rack / bins, I just take one out and machine it. In retrospect, I should have marked it, but I didn't, it's in the bins now. Hindsight is 20/20. I DO mark the stuff when I find it.

Mcgyver
12-28-2009, 11:01 PM
l!

Mcgyver - Keep in mind that the instantaneous temperature at the tooth can be pretty high, even when the blade is running slowly.

agreed, temp and heat is often confused, its temp which is mostly dependent cutting speed that we need to worry about aging the tool steel blade...and coolant wont help much either. Its theorizing for me, i'm using a bimetal blade. As i think more about it it might not be practical to slow the blade down enough that temp didn't affect the edge....still a if I had a blade welder it would be worth looking into the cost of a roll and putting the saw at its slowest speed. I like solutions that have a 30 year life span siting on the shelf vs having to stop work or runabout picking up another $30 blade :D. All idle talk until i stumble over a $5 blade welder

darryl
12-29-2009, 12:13 AM
I won't even buy a carbon steel blade for my hacksaw anymore. About all I find them good for is friction cutting- and it doesn't matter which way you put them on. In fact, with the teeth to the back it seems to cut better- :)

Fasttrack
12-29-2009, 12:21 AM
agreed, temp and heat is often confused, its temp which is mostly dependent cutting speed that we need to worry about aging the tool steel blade...and coolant wont help much either. Its theorizing for me, i'm using a bimetal blade. As i think more about it it might not be practical to slow the blade down enough that temp didn't affect the edge....still a if I had a blade welder it would be worth looking into the cost of a roll and putting the saw at its slowest speed. I like solutions that have a 30 year life span siting on the shelf vs having to stop work or runabout picking up another $30 blade :D. All idle talk until i stumble over a $5 blade welder

Yep. We had some rolls of "Starrett" brand carbon steel blade at one of the shops I worked in. It was handy having it on the shelf, although I found myself making up blades about once every two weeks. The saw did get used pretty heavily and we never put a bimetal blade on it, so I'm not sure how they would compare.

MTNGUN
12-29-2009, 12:49 AM
if I had a blade welder it would be worth looking into the cost of a roll and putting the saw at its slowest speed. I like solutions that have a 30 year life span siting on the shelf vs having to stop work or runabout picking up another $30 blade :D. All idle talk until i stumble over a $5 blade welder
Shop Floor Talk has a thread by Florida Jim on brazing bandsaw blades. He uses a simple homemade jig. I'm always too busy to try making my own blades, but if I had time, I'd give his method a whirl.
http://www.shopfloortalk.com/forums/showthread.php?t=16414&highlight=brazing

I use carbon on my 4x6 to cut 1/4" round stainless because bi-metal is not available in the fine tooth sizes for the 4x6. I don't keep records on blade life, but it seems like the carbon blades last at least one month cutting mostly stainless (the 4x6 is currently dedicated to that one job).

Of course, the saw does not run 24/7, so one month in my shop may not be the same as one month in your shop.

Blades generally last longer on my 7x12 than on the 4x6, probably due to the 7x12's coolant system. Carbon blades typically last 2 - 3 months, so I am happy to use carbon. But, last time I ordered blades, Enco had their bi-metal on sale so I stocked up and will be switching to them.

Before acquiring the 7x12, the 4x6 had to saw everything and it used bi-metal for larger stock. On the 4x6, the bi-metal blades averaged about a month -- which is about how long carbon blades last on the 4x6.

In general, I've been happy with carbon blades and don't see a big improvement with bi-metal, and I cut a lot of "difficult" metals -- stainless, 4140, and scaly ductile iron. I do run my saws on a slower than recommended speed -- I have to run it slow for stainless, so I just leave it on that low speed all the time, even for aluminum.

darryl
12-29-2009, 03:35 AM
Well, I must have run mine too fast cause I couldn't get more than a couple days out of a carbon blade.

Peter N
12-29-2009, 03:44 AM
Another vote for Lenox Diemaster II Bi-Metal blades.
I run the 6-10 vari-tooth blades as I rarely use the bandsaw for anything smaller then 3/4" or so, and they work very well and last for ages.

As a matter of fact they're so good that a six-month old blade in my bandsaw still cut up the pre-hard 2085 stainless (modified 420 stainless) into much more manageable lumps. The original size was 420mmx360mmx40mm.

http://www.btinternet.com/~p.neill/Tooling_plate_cut.jpg


Peter