One blade I had been using for years was the Evolution 36-tooth multi-purpose blade that I just recently had re-sharpened at W.D. Quinn, and for occasional metal cutting it works ok. Definitely not optimum, but it does cut steel. I used it for so long simply because it came with my Rage 2 saw and it sees limited use for my projects.
In stock form it has a standard alternating bevel, but W.D. Quinn puts a modified alternating bevel on the carbide tips when they sharpen it, like so:
Cutting thin material (<3/16") with it is risky because you can easily loose carbide tips if you feed the blade in too fast. It can be done, but just have to go slow. 3/16" (single-layer, like flat bar) is what I would call a good lower-limit for cutting steel. 1/8" for angle/channel/tube since it has multiple-layers to go through, effectively making it seem like a thicker material to the blade. For solid round, I'd guesstimate about 3/8" diameter. Cuts PVC/plastic and wood pretty good.