1000 oz Silver Bars are truly the king of silver bullion bars. These are the silver bars poured by silver refiners when creating pure silver from silver ore, and should ideally fall within "Good Delivery" criteria (see below). Typically cruder in style than the smaller minted bars, the 1000 oz bars do not weigh exactly 1000 troy ounces, but owing to the manufacturing process have an weight between approximately 900 and 1050 ounces. 1000 oz bars are typically poured (cast) as opposed to minted, and are manufactured by major LBMA-accredited or COMEX-accredited bullion producers, such as Johnson Matthey. Bars will be stamped with a serial number, purity, weight and assay mark. Eligible for Precious Metals IRAs.