Monel® K-500 (UNS N05500) is an age-hardened nickel-copper alloy used for high-strength, corrosion-resistant components such as fasteners, valve stems, pump shafts and marine hardware. Age hardening gives it two to three times the strength of Monel 400, and it retains these mechanical properties up to about 650degC while offering excellent corrosion resistance in both chloride-containing and chemical environments.

We hold a comprehensive stock of Monel K-500, from 5/8" (15.875mm) to 10" (254mm) diameter solid bar. At times in our history we cast our own ingots for further processing; today we work closely with our mill partners to provide a competitive offering.

Common applications by bar size

Bar around 1" (25.4mm) diameter is most popular among customers who manufacture fasteners. Given how universally fasteners are used, these can find their way into marine atmospheres, pumps and valves, and components in the chemical processing industry.

Slightly larger bar, typically 1-2" (25.4-50.8mm), is most commonly ordered by valve manufacturers to produce stems in a variety of valve types. Aluminium bronze is a common choice for the cast bodies of valves handling seawater and chemicals, with Alloy K-500 providing similar corrosion resistance. Its high strength and toughness across a range of operating conditions reduce the likelihood of damage to the stem through misuse or sticking of the valve in operation.

Mid-range bar, typically 3-4" (76.2-101.6mm), is purchased for a wider array of applications. Alloy K-500 is used in the fabrication of specialist marine and naval hardware, through this combination of high strength and durability in seawater. At these sizes it is also used to produce pump shafts, most commonly for firefighting and seawater-lift pump systems. Propeller shafts are a target application but less common, as duplex and super duplex stainless steels are more widely used for their significantly lower cost.

Larger bar, between 6-10" (152.4-254mm), is most commonly machined into the bodies of valves, usually for service in the chemical process industry given the wide range of media this alloy can resist.

Other applications for Alloy K-500 include drill collars and instrumentation used in oil well drilling equipment, thanks to its resistance to seawater and sour gas environments. It is also used in aerospace hardware, chemical processing equipment such as doctor blades and mixers, springs, pump sleeves and wear rings.