2.4375 Monel K-500 N05500 Nickel Alloy

Grade	Code	UNS	Nickel Alloys
Monel K-500 / Alloy K-500	2.4375 / NiCu30Al	N05500	Nickel Alloys

Nickel Alloy Properties

Monel K-500 / Alloy K-500, a nickel-copper based alloy, combines the corrosion resistance of Monel 400 with higher strength and hardness. These improved mechanical properties are achieved by adding aluminum and titanium to the nickel-copper matrix and subjecting the material to controlled ageing heat treatment. During this process, very fine Ni₃(Ti,Al) precipitates form within the matrix and increase the strength of the alloy. This heat treatment is generally referred to as ageing or precipitation hardening. Its low magnetic permeability, good dimensional stability and reliable performance under demanding service conditions make this grade technically distinctive.

Chemical Analysis (Monel K-500 / Alloy K-500)

Ni+Co %	Cu %	Al %	Ti %	Fe %	Mn %	Si %	C %	S %
63.00 min.	27.00 – 33.00	2.30 – 3.15	0.35 – 0.85	2.00 max.	1.50 max.	0.50 max.	0.25 max.	0.01 max.

Mechanical Properties

Product form	Condition	Rp0.2, MPa	Rm, MPa	Elongation, %	Hardness	Density, g/cm³
Bar	Hot-finished, aged	690 – 1034	965 – 1310	20 – 30	265 – 346 HB	8.44
Plate	Hot-finished, aged	690 – 981	965 – 1241	20 – 30	265 – 337 HB	8.44
Sheet / Strip*	Cold-rolled, annealed + aged	621 – 827	896 – 1172	15 – 25	24 HRC min. / approx. 250 HB	8.44

* Note: The sheet/strip row should be used as an approximate/representative value for thin flat products. In the source table, hardness for this product is given as 24 HRC min.; since HB is not given directly, approx. 250 HB should be treated as an approximate conversion. HB values for bar and plate are given directly in Brinell. The values are nominal room-temperature ranges and should not be used as guaranteed specification values.

Application Area

Industry	Products
Marine / Shipbuilding	Propeller shafts, seawater pump shafts, marine fasteners
Offshore / Offshore Platforms	Bolts and studs, wire rope armoring, seawater-exposed connection parts
Oil & Gas	Drilling equipment components, oil-well tools / downhole tools, valve trim components
Chemical Process Industry	Pump shafts, valve components, wear rings
Petrochemical / Refinery	Pump bushings, valve sealing elements, process equipment connection parts
Pump & Valve Manufacturing	Pump shafts, pump sleeves / bushings, valve trim / internal valve parts
Paper & Pulp Industry	Doctor blades, scraper blades, blade holders operating in abrasive media
Aerospace / Precision Equipment	Aircraft instrument components, springs, precision fasteners requiring low magnetic permeability

Description

Monel K-500 / Alloy K-500 owes its high corrosion resistance mainly to its nickel-copper matrix. The high nickel content helps the alloy remain stable in many corrosive environments, while copper supports resistance particularly in seawater and salt-containing media. Aluminum and titanium are used mainly to increase strength and hardness through ageing heat treatment, rather than to provide the primary corrosion resistance. Therefore, Monel K-500 / Alloy K-500 is regarded as a grade that combines corrosion resistance similar to Monel 400 with higher mechanical performance. However, it should not be considered resistant without limitation in every environment; stagnant or low-velocity seawater may create a risk of pitting, and stress corrosion cracking sensitivity should be considered in special environments and high-stress service.

Specification

Monel K-500, Alloy K-500, UNS N05500, W.Nr. 2.4375

Standards

Form	Standards
Bar / Rod-Bar	ASTM B865, ASME SB865, SAE AMS 4676, DIN 17752, ISO 9723
Plate	QQ-N-286, DIN 17750, ISO 6208, BS3072 NA18
Sheet / Strip	QQ-N-286, DIN 17750, ISO 6208, BS3072 NA18 / BS3073 NA18