How to cut wear resistant steels?

F

fields_mj

Joined
Nov 29, 2015
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Just curious how people are cutting bar stock for wear resistant steels like 10V or S90V. I used my portable bandsaw to cut some S90V this weekend using some Lenox blades. One blade would last long enough to cut one blade out and then it was done. The blade would go from cutting just fine to not cutting in less than 5 seconds. Didn't know if I was doing something wrong, if there was a better brand/type of blade to use, or if this is just the cost of using high alloy steels.

Thanks,
Mark
 
I use a quality portaband saw blade and am able to rough profile 3-4 S90V blades per saw blade. For S110V, I still use the drill-and-connect-the-dots-with-a-chainsaw-file method.

What helped for me was ensuring the speed was lowered and the pressure was constant. too fast and you kill the teeth, too light and the blade burns the steel and work hardens the area.
 
With a proper bimetal blade I don't see any problems with the bandsaw. I have cut plenty of m390 k390 and Magnacut with my current blade (floor standing unit, so longer blade)
 
navman said:
I like where you are going with this...but I would probably choose waterjet over plasma. I have used a local plasma cutter guy when I was in Virginia and had some issues with hard steel at the edges. If I were doing another large batch, I would find a waterjet place.
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For batches, laser or water. I use plasma for small stuff. A handheld cheap china stuff. Works great up to 6mm. Over that HAZ is bigger. Hardened edges are easily ground of with an old belt. Just push. :D
 
Are you using coolant? Makes a mess, but if your steel is annealed and you're using a bimetal blade as S Scaniaman said I would think you would be okay. I use a water based coolant. I haven't cut to much wear resistant stuff only z- wear and not sure if Apex ultra qualifies. Don't let it work harden.
 
Sando said:
Just wondering, but how thick is the steel and what's the TPI on the blade?
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The S90V was 1" x 3/32" (mill finish so more like 0.110"). I went through two blades that were 22 tpi, and 2 more that were in the 12 tpi range. One of the 12 tpi blades was used when I started and only made it through 3" before it stopped. That's when I switched over to the 22 tpi blades. Each of those blades cut through a little over 6" before blunting. If I pushed hard enough, it they would still cut, but I was concerned about work hardening the material. Those were the only two 22tpi blades I had so I put a 12 tpi blade back on to do the last cut. It's toast now, but it got the job done :)

I've always had decent luck with the Lenox blades lasting on my portable bandsaw. They seemed to be soft enough that they don't quickly snap at the seam, but hard enough to cut for a while. Then again, I'm normally cutting low carbon hotroll, or A36 with them. I've used Morse blades in the past, and the teeth hold up really well, but the blades normally snap pretty quick even if I'm using light pressure. In my case, it sounds like it might be a technique issue.

I thought about using some coolant/lube, but not easy to do with a portable bandsaw, especially since I really needed to make an accurate cut due to where I had the blades laid out relative to each other.

I have some 0.040" cut off blades for my 4-1/2" grinders. I thought about using them, but I had 2 sets of the blades pretty close together and wanted the extra control that I can get from the bandsaw. If I do any more, I'll have to give myself more room and use the grinder more than the bandsaw. After profiling the blades, I quickly came to the conclusion that trying to make semi accurate cuts with the bandsaw to save time on the grinder was a waste of time. Grinding material away with a 36 grit belt was MUCH faster :)

If I were doing them in bulk, a local weld shop has a water jet that would be useful. These blades are just for me at this point though.

Thanks for all the info and suggestions!
Mark
 
Hmmm, for 3/32" you shouldn't go below 18tpi. As I understand it (and I'm sure the machinists here can be more specific), you really should have 2 or 3 teeth in contact with the steel at all times. Otherwise, the teeth will catch and it'll knock off the carbide tips. So, 3/32" will take out a 12TPI blade pretty fast.

That said, the 22TPI blade should work just fine. Like S Scaniaman and navman navman I haven't seen what you have. (I use a lot of Elmax and MagnaCut.)

FWIW I use a cutting-lube stick and smear it over the cut lines before I start, but I'm not sure how much that helps.
 
i use a 64 1/2 inch bladed band saw and have cut dozens of blades out with a single blade..
from elmax to lots of 154cm to 14 c28 to N690.. hell i think i only change out the blade1-2 times a year..
i don't know what you could be doing to only cut out a few ..
do you cut aluminum /titanium/soft metal for a while before beating on it ???
 
Are you breaking in the blades? Check out the search engine. I used to not break them in until someone used the analogy of a freshly sharpened pencil. If you write softly it will round the tip and write for a while. If you jam it onto the paper it will break the tip off.
 
Jasonfromvk said:
Do not use a plas table with this stuff correct. Jesus christ i get dumber everytime I try to help people here. An angle grinder works the best in my experience unless you have an extremely expensive bandsaw.


Laser also is a no. I won't even etch my own blades because of the surface temps.
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Extremely expensive bandsaw with cheap band saw blade is what ? :) For one , two blade at time my angle grinder is enough to get close to shape .
 
I have had steels from time to time cause havoc on portable band saw blades. The worst have been a piece of 1/8 Magnacut flattened at AKS and a strip of 3/32 S45VN that absolutely destroys fresh band saw blades.
 
Yeah, i used the the 12 tpi because it was already on the saw, and it was the only thing i had left to finish the last cut with. If you down to less than 2 teeth in the material, the chip load becomes very inconsistent. This causes vibration which is essentially lots of small impacts and thats not good on cutting surfacs. I am extremely familiar with what happens when one breaks off. 😕 Thankfully, that didn't happen with any of the blades.

Unfortunately, no I did not properly break in the blades when I changed them. My experience has been that the break in helps keep the blades from snapping, especially on portable bandsaws. Since my blades didn't snap, I'm not sure that a break in would have really helped me. You bring up a good point on the sharp pencil though (no pun intended). Seems like in that analogy, I would have first had dull spots on my blade. Still, a break in could not have hurt so I'll keep that in mind next time.

Talking to a couple of machinists this morning and they brought up a good point. While I don't think I work hardened the S90V (because the next blade resumed the cut with no issues), it's possible that I got the teeth hot on the blade. The blade didn't smoke, or feel warm when I removed it, but if the heat was isolated to the very tip of the teeth, I suppose that could have caused the blade to go from sharp to dull almost instantly. I didn't think I was pushing too hard, but I'm used to cutting low carbon hot roll with it. Its very possible that with the high alloy steel, I could have been pushing too aggressively causing the dry teeth to loose eventually loose their temper and go from cutting great to a dead stop almost instantly. Interestingly, feeling the blade afterward with my thumb, it didn't actually feel dull. It wasn't cat's paw sharp like a brand new blade, but it felt pretty good. Overheating and dulling the very tips of the teeth would have this effect.

We use parifin a lot at work, but we smear it on the blade before we start a cut. If I buy any more blade steel I'll make sure to do a break in, get some Morse 22tpi blades, and use some beeswax to for lube.
 
fields_mj said:
Yeah, i used the the 12 tpi because it was already on the saw, and it was the only thing i had left to finish the last cut with. If you down to less than 2 teeth in the material, the chip load becomes very inconsistent. This causes vibration which is essentially lots of small impacts and thats not good on cutting surfacs. I am extremely familiar with what happens when one breaks off. 😕 Thankfully, that didn't happen with any of the blades.

Unfortunately, no I did not properly break in the blades when I changed them. My experience has been that the break in helps keep the blades from snapping, especially on portable bandsaws. Since my blades didn't snap, I'm not sure that a break in would have really helped me. You bring up a good point on the sharp pencil though (no pun intended). Seems like in that analogy, I would have first had dull spots on my blade. Still, a break in could not have hurt so I'll keep that in mind next time.

Talking to a couple of machinists this morning and they brought up a good point. While I don't think I work hardened the S90V (because the next blade resumed the cut with no issues), it's possible that I got the teeth hot on the blade. The blade didn't smoke, or feel warm when I removed it, but if the heat was isolated to the very tip of the teeth, I suppose that could have caused the blade to go from sharp to dull almost instantly. I didn't think I was pushing too hard, but I'm used to cutting low carbon hot roll with it. Its very possible that with the high alloy steel, I could have been pushing too aggressively causing the dry teeth to loose eventually loose their temper and go from cutting great to a dead stop almost instantly. Interestingly, feeling the blade afterward with my thumb, it didn't actually feel dull. It wasn't cat's paw sharp like a brand new blade, but it felt pretty good. Overheating and dulling the very tips of the teeth would have this effect.

We use parifin a lot at work, but we smear it on the blade before we start a cut. If I buy any more blade steel I'll make sure to do a break in, get some Morse 22tpi blades, and use some beeswax to for lube.
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There is Always time for lubrication!

I use old "soap" bars that my wife used to try to make on a crafty whim..... they got rock hard over the years, and work great for what I want.
 
The lack of lube wasn't really because I didn't have time. It was because I was only thinking of the oil based lubes that I have in my shop. I needed 2 of the (curved) cuts to be relatively accurate because I layed the blades out so close. I was concerned that an oil based lube would make it more difficult for my tired eyes to keep the wondering bandsaw blade on course. If I had thought about it some more, I would have grabbed a stick of chapstick from the house, or one of the small utility candles that we've never used in 25 years, or I would have sacrificed the small block of beeswax in my archery tool box.

I've cut a lot of steel over the years with a bandsaw. Most of it was at work (machine shops at various integrators and manufacturing plants). Most of it was cut dry with no ill effects from a lack of lube. I haven't noticed a HUGE difference in tool life between lube vs no lube except when cutting aluminum alloys. Having said that, when someone else is buying the saw blades but I'm cleaning up any mess from the lube, my perspective probably gets skewed. On saws with flood coolant, I've always used it because the mess is the same regardless.
 
I had to cut out 8 S90V blades a few months ago. Blade would be cutting good and then just stop. I wondered if there were hard spots/carbides in the steel or something? I used a Dremel cut off wheel to do connect the dots and a hacksaw for some of the cutting. I think I went thru 2 blades to cut the 8 blanks? Now I gotta grind 8 blades in S90V after hardening. 2 of the blades are 18" x 2.5" wide, just under 1/8" thick. Not looking forward to that!
 
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