Monel k500 Threaded Flange, Slip On Flange, Blind Flange – Monel k500 Flange Manufacturer Superior Quality ASTM B564 Monel k500 Orifice Flange and Slip On Flange at competitive prices. Monel K500 is a precipitation-hardenable nickel-copper alloy with similar corrosion resistance properties to Monel 400,