Designed for lifting plate material in horizontal position. Heavy-duty steel construction for years of reliable use. Meets ASME B30.20 specifications. Do not use plate clamps to lift loads less than 20 percent of rated capacity. Lift only one plate at a time. Plate must be clean and free of oil. 400 Pounds min uniform plate weight. Not designed to use on stainless steel or aluminum plates. For use with materials with a surface hardness to 30 RC (300 HB).