Cut-off wheels and flap discs...

[68protouring454]

for a 4.5 grinder, sait makes .045 cut off wheels that are killer, we run 5 inch ones.
mac also makes 3 inch roloc flap disks that rock as well.
for reg roloc i use carbo blaze (orange) 36/50 grit, about 35 bucks for a box of 25.
the roloc flap disks are the best thing ever

sait cut off wheels are best hands down.
msc has them
autobody supply houses should have the carborundum rolocs, btw i hate 3m stuff