Gunsmithing Bandsaw blade question

[chipsfan]

I have a Powermatic 143 metal cutting bandsaw. I want to cut some 1/8" o1 flatdstock for knife blades.

What kind of blade should I be using? Should the speed be all the way down.

It hasn't been working so well

 

[JJones75]

That material is a bit harder than the saw blade so its gonna be a pain to cut.
I'd run the blade speed down to 50-60 feet per min and use decent down force pressure , use a good thick cutting oil and keep the blade wet with it.
best bet would be with an abrasive chop saw or cut off wheel on a hand grinder.

 

[chipsfan]

That material is a bit harder than the saw blade so its gonna be a pain to cut.
I'd run the blade speed down to 50-60 feet per min and use decent down force pressure , use a good thick cutting oil and keep the blade wet with it.
best bet would be with an abrasive chop saw or cut off wheel on a hand grinder.

Thanks. That would make sense based off my experience.

 

[CNJarvis]

I use a cutoff wheel on my angle grinder to cut and rough out blades in O1, 1095 and 154CM. It's more trouble than it's worth to me to cut it with a saw.

 

[VoxPatriam]

I've tried what you're talking about with less than fantastic results. Honestly your best bet would be to find a shop with a CNC plasma cutter, give them a drawing of the design and have them cut it out. I've been making these breacher's axes for friends and I got seriously tired of cutting them out by hand. Even with a 1/4" band saw blade going slower than Obama talks, it just wasn't where I wanted it to be and I spent an inordinate amount of time with a grinder finishing the blades.

 

[MikeeBooshay]

Chop saw is the way to go.

I once had to scrap a PILE of gas turbine blades - so that they could never be used again. I bought a cheap Dewalt chop saw and a bunch of carbide cut off wheels - made pretty quick work out of that. Millwrights threw one in the clamp, plunged the blade thru it - two pieces, your O1 is not nearly as hard as Inconel, should work out fine.

 

[CS223]

If it's annealed 0-1, is should cut as easy as anything else. If you're trying to cut a hardened piece then you'll have to use one of the suggested methods. Make sure the blade you're using isn't too coarse, you need a min of 3 teeth in contact with the material so you'll need at minimum a 24TPI blade.

 

[LRI]

Usually when a guy buys O-1 its in an annealed state. This way you can machine your part and heat treat it somewhere towards the end of the process. (say when it's done, or right before finish grinding)

So, assuming this is the case and recognizing that your having troubles it's likely one or a combination of the following:

1. Dull blade causing material to work harden. -replace blade
2. Too high a SFM causing material to work harden and blade goes to shit. -lower your SFM and replace blade.
3. Wrong tooth count for material's physical shape. two teeth in contact at any given moment is a good rule to avoid the blade bouncing on the part. This destroys the cutting surface very quickly. Also leads to blade breakage.


Oil is fine assuming your observing #2. Another solution would be to use a water based coolant as it'll mitigate work hardening much better than oil. Oil sucks at removing heat. Water kicks ass.

Last, Take my advise with salt, but a chop saw and/or cut off wheel is the last tool I'd be looking to use when working with a material like O-1 or any tool grade steel that I'm trying to machine a part from. Reason is these friction based cutting tools introduce a tremendous amount of heat into the material. It could very well harden that area making it a real chore to machine. It could also anneal an already heat treated part, making it junk unless its run back through the process.

They may very well cut through the material like butter. Not arguing that. All I'm saying is there's a reason that tool grade steels exist. It's so that they can be heat treated for added strength, hardness, toughness, "springyness", etc. It's important to be in control of when this heat treat process takes place. Control that by using sharp tools, the right tool, and observing well established speed and feed rates.


Hope this helps.

C.

 

[MikeeBooshay]

It could very well harden that area making it a real chore to machine. It could also anneal an already heat treated part, making it junk unless its run back through the process.

They may very well cut through the material like butter. Not arguing that. All I'm saying is there's a reason that tool grade steels exist. It's so that they can be heat treated for added strength, hardness, toughness, "springyness", etc. It's important to be in control of when this heat treat process takes place. Control that by using sharp tools, the right tool, and observing well established speed and feed rates.


Hope this helps.

C.

One of the best fillet knives I ever used, my dad made from an old power hacksaw blade, when stuck on a ship, with no liberty ashore. Two or three passes on the grinder, then dunked in a bucket to cool, over and over, took forever, but the end product was worth it.

When OP mentioned it was a knife blank from 1/8 stock, my thought was that he would still have to heat treat it, just use something fast and easy, most of what he had left to do is grinding anyway, nothing that the chopsaw would hurt. We machine a lot of parts after welding on them, most get a full solution anneal to soften up, then machined and additional anneal cycle done, while held in a fixture to minimize warpage. Unless it's EDM, most machining does release enough stress, to cause some dimensional changes. OP doesn't appear to be worried about that here, just how to make knife blanks from a piece of flat O1.

 

[NCKan]

I use a metal cutting bandsaw for cutting all of my cutlery steel. I belive my blades are 18 tpi, run as slow as your saw will run. I cut D2, A-2, 0-1, 440, 52100, S-7....all types, as long as they are annealed. Save yourself a big headache and by the best quality blades you can find. I know one knifemaker that cuts five or six blanks at a time all stacked on top of each other, but he has a very large bandsaw. The only time I use a chop saw, is for cutting hardened steel and Chad is correct, you ruin the steel on both sides of the cut. I don't make enough knives to justify the cost, but the utlimate way to cut out blanks is to use a waterjet. If you are only doing a few blanks, and you have the design, you might find someone near you to waterjet them.
01 makes a very good blade and is easy to heat treat, but you can almost watch it rust. Consider a coating like ceracoat. You might be suprised how well it cuts.
Good luck.
JSS

 

[burkeknives]

Just order a bimetal blade from MSC, then you will have no problems. And yes, run it slow.
I use them to cut all types of steel, S7, 3V, A2, on and on.

I am assuming it is annealed, non hardened?

If you have any questions, shoot me a PM.