Abrasive cutoff wheels are slow, especially when cutting on the flat side of the square stock. Your wheel is most likely fine, it’s just the nature of the beast. Take your time, don't force it and let the wheel do the cutting.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum