What are the recommended cutting speeds for the Spectrum 375 at different amperages?

At 30 amperes output on mild steel, cutting speeds range from 104.8 ipm for 12 gauge to 6.4 ipm for 5/8 inch thickness. At 27 amperes, speeds range from 115.0 ipm for 12 gauge to 4.8 ipm for 5/8 inch. At 20 amperes, speeds range from 158.4 ipm for 1/16 inch to 6.4 ipm for 3/8 inch thickness. These recommended speeds are approximately 80% of maximum, and aluminum and stainless steel cutting speeds may be reduced as much as 20%. (Page 20)