Do I need a slow-speed bench grinder for sharpening tools?

For woodturning gouges, chisels, and plane irons, reviewers across specialist forums strongly prefer a slow-speed (roughly 1725 RPM) grinder because it generates less heat and is less likely to draw the temper out of tool steel. For general metalwork, deburring, and shaping, a standard 3450 RPM grinder is fine. Several picks in this list are 1725 RPM specifically for sharpening duty.