Physics lesson needed.....abrasive cut off performance

[ampedtech]

Often when cutting off larger thicker steel with an abrasive (made for steel) 14" cut off the sparks and cutting stop and the steel gets hot.

I can detect the the "blade" is hot but only for a very short time.

Even after the blade and steel cool several min. it will not cut unless I wait for a long period of time, about an hour it will cut again.

I know the problem is the blade cause if I put in a fresh blade I can cut immediately.

What is going on?

going to go try to finish the cut in a 3/16" x4"

[BD1]

I have the same thing happen. The blade gets a glaze on it and it won't cut. Try cutting some thinner or light gage material to remove glaze.

[MMW]

If you don't push down consistantly it helps. Like alternating between pushing down & letting up on the handle. I have also flipped the abrasive disc around. Just make sure it isn't directional. You can also try a lube while cutting. Sometimes I use wax (http://www.mcmaster.com/#lubricant-stick-wax/=l7zxs1) or wd-40.

Sorry can't give you the physics lesson.

[Portable Welder]

When cutting flat bar in an arbrasive saw try cutting it standing up verses it laying flat, I would always keep steady pressure, If you let off in the midddle of a cut the steel hardens and when you start back you have to heat it back up again before it wants to cut.

I wouldnt put any oil on the blade ( You dont want it to deteriorate and shatter).

If your cutting it in a band saw then you want to lay it down flat.

[Cgotto6]

Purchasing quality wheels is important too. I am yet to find anything that works as good as Sg Elastic products.

[benA]

The lower quality disks are especially bad. The grit glazes and stops wearing away, thus just making more heat. When I used to use a chop saw alot, I had a piece of spring steel that I would touch to the disk and break the glaze off so it would keep cutting.

[elvis]

I try to keep the surface area of the cut as small as possible. The example of flat stock works well for me. Also, c-channel I'll stand on end and I do that with smaller angle iron (1.5"x1.5"). "pulsing" the pressure helps and I try to keep the RPMs up on the blade. I have been using the diablo 14" abrasive cutoff blades and they have been decent. Readily available. I think part of it is just practice? Finding the fastest and most efficient way to cut without damaging the parent material.

Good luck.

[Helios]

Those big abrasive wheel cutters suck. I hate em. I only use mine now if I can't cut the piece with either a Porta-Band saw or a small cutting wheel on an angle grinder...which means "almost never."

I think I'd rather try to chew through the cut with my teeth than use a 14" abrasive cutter.They take forever, they make a racket and they usually make a lousy cut.

[Kpack]

Seems like the long life blades are the worst for glazing try a fast cut blade the fast cut are getting harder to find I think the last one I got was at grainger.

[Country Metals]

The lower quality disks are especially bad. The grit glazes and stops wearing away, thus just making more heat. When I used to use a chop saw alot, I had a piece of spring steel that I would touch to the disk and break the glaze off so it would keep cutting.

Second that, just like steel can be hardened, the grits on the wheel can get "hardened" Think of it more as using a hole saw through plastic. If you use a 3" hole saw to drill through 1" plastic with a lot of pressure and speed, you will melt the plastic, and once it gums up on the teeth, you will never cut until the teeth are cleaned.

I would just use another piece of metal and "clean" the wheel, and keep going. I never did try switching the blade around, that seems like a good idea.