Whether you use a belt or stone, you start at the edge of the bar and work across it .010-.030" or so each pass. The leading edge of the wheel is doin most of the work, so a 1/2" wide wheel will do fine & at half the cost of a 1" wheel. I've actually never seen a 1" wheel on a surface grinder, but some of the big ones might use that size?
I use 1" thick wheels on my Landis 618 Hydraulic, but it has flood coolant. Not that I always use it, but definitely on thin stock.
It also has a 3" spindle adapter, which it's hard to find 1/2" thick wheels with 3" hole.
FWIW I normally use one of those Norton 32A wheels also, that Don recommends. Since that's what I've got, I also use the Radiac POR-OS-WAY ruby wheels and a Norton 5SG Ceramic on my Do-All 612, which is a smaller SG. The 5SG if you can find them, are just a ceramic alumina wheel, very similar otherwise to the equivalent 32A, although both of them come in various grit, hardness, bond, and friability. The speed the friability and hardness will affect the speed with which they break down, which affects the aggressiveness and heat build up.
Every manufacturer uses different codes also, which aren't standardized. Check out this file for a guide on Norton's wheels:
http://www.nortonindustrial.com/upl...s/Documents/Toolroom Selection Chart 7505.pdf
For instance, I'm using a Norton 5SGP70-K8VH 7x3/8x1.5 wheel to cut my nail nicks. I would have bought a finer grit but I bought this wheel because it was the only "VH" code wheel I could find, which is a more closed structure wheel with high "form holding" capability. This means it's able to hold a sharp dressed corner edge angle, which is what I found I needed for nail nick clarity.
I tried numerous more porous wheels and they sucked.
