Specification - P4120 - 12in Square Heavy Duty Stainless Steel Floor Sink MIFAB series P4120 - 12in square heavy duty floor sink constructed of 14 gauge, Type 304 stainless steel. Free area of 51 square inches. Standard with ANSI rated "Heavy Duty" slotted Type 304 stainless steel grates with a load rating of 5,000 to 7,500 lbs and no hub bottom outlet.