Metal caps offer the widest range of temperature tolerances and are very resistant to fracture from impact. Metal caps are great for industrial and food applications. A metal closure is manufactured from either steel (coated with anti-corrosive coating of either chromeplate or tinplate) or aluminum. White Pulp/Polyethylene Lined Metal Caps are a great general purpose closure. They are ideal for powders and non-acidic food products and consumer products such as jar candles and honey.