You are thinking like a real home shop machinist now! Kudos for creativity.
Many of us have found that any kind of abrasive saw is suboptimal for home
use. They are loud and messy and unsuitable for stock of much thickness. I
have had offered to me 2 different metal-cutting chop saws. I brought one
home and ran it a couple of times and then gave it back even though it was
free to me. Those are really made for cutting metal studs, which are basically
sheet metal. They didn't work at all on 1" steel square bar -- I hit a hard
spot and it just got harder and in the end the saw wouldn't cut it. The little
4x6" band saws are much quieter, cleaner and safer.

If you want an abrasive saw, you might look around your local area first for
a used one. I see them all the time as guys buy them thinking what you're
thinking, and then they realize their limitations and then they try to sell
them and then they realize there isn't much market so if they're smart then
they give them away or really really lower the price. My target price would
be $20 or less but only if the saw looked new, and only if I were you.

The market may be different where you live.

You might find the 4x6 FAQ interesting:

http://www.tinyisland.com/4x6bsFAQ.html

GWE

Ron M. wrote:

I want to put an abrasive metal-cutting wheel on a miter saw, to cut
mild steel angle with. Most of this will be 3/32" or 1/8" 1-inch angle.
Some say, "sure, no problem!" while others say, "the horror, the
horror..." The purpose is to cut a few pieces for some welding
projects. For example, cutting some angle steel at 45 degrees to make a
table top.

Now, before this goes any further, please do *NOT* tell me to "go buy a
chop saw" or "buy a used band saw" or whatever. I'm talking about a
miter saw ONLY, OK?

There are supposed to be two main issues with doing this:

First, it overloads the motor. But I don't think this would happen, if
you just use very light pressure and take your time and go slow.

Second, the shavings/sparks can damage the fence and/or the motor
mechanism (bearings). There may be some truth here. The fence shouldn't
be a problem, and I can always cover it with something. Particles? Some
suggest removing the vacuum. How about attaching the nozzle of my shop
vac just behind the blade and letting it catch them? Or maybe putting a
big magnet there, perhaps.

This isn't something I'll be doing often. Maybe once a month I'll make
3 or 4 cuts, at the most, no more. As I said, 99% is going to be
cutting 45 degree ends in 1/8" X 1" angle, so I can join them together
to make a square corner. That's it.

I use an abrasive blade in my circular saw for straight cuts, but it's
hard to cut accurate angles with it. I also have a Porter-Cable Tiger
sawzall, I don't think that would work well for this kind of cutting,
although I've never tried it.

Please give me a tip here, especially if you've actually done it, and
aren't just repeating what you've read or heard. And PLEASE don't tell
me to "go buy a chop saw"!!!

Thanks,
Ron M.