Air Cutting Tools
Once you take the jump to having an air compressor in the shop, you'll find that compressed air is better than electricity at all sorts of jobs.
For abrasive cut off wheels, air power is great. With almost no effort an air powered cut off wheel will spin up to 15,000 rpm or more, and make short work of anything and everything. The reciprocating air powered pistons in shears, nibblers and saws can work the same magic in thinner sheet metal and the like.