Monel K500 Round Bar
➡️ Alloy K500 | UNS N05500 | EN 2.4375
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Nickel Alloy
UNS Number:
N05500
Wr. No.:
2.4375
MTC Available:
EN 10204 3.1
Product Description for Monel K500 Round Bar
Monel K500 is the age-hardenable version of the nickel-copper alloy family, UNS N05500 and Werkstoff 2.4375. Bar is delivered against ASTM B865, the standard covering age-hardenable nickel-copper alloy rod, bar and wire.
It takes the Monel 400 composition and adds 2.30-3.15% aluminium and 0.35-0.85% titanium. During ageing those form a gamma prime precipitate that roughly triples the proof strength, taking it from 195 MPa in annealed 400 to 690 MPa minimum here, while keeping essentially the same corrosion resistance in seawater, brine, alkalis and hydrofluoric acid.
Bar is solution annealed at around 980 C then aged at approximately 595 C for 16 hours with a controlled furnace cool. Machining is normally done before ageing where geometry allows.
Two properties distinguish it from Monel 400 in practice. It is reliably non-magnetic, because the aluminium and titanium additions push the Curie temperature far below ambient, unlike 400 which sits near room temperature. And it is non-sparking, which is why it appears in tools for explosive atmospheres.
One caution is important. In seawater under cathodic protection, aged K500 is susceptible to hydrogen embrittlement, and there have been fastener failures in subsea service. Hardness limits under NACE MR0175 apply.
The modulus of elasticity at 179 GPa is the same as Monel 400 and well below the roughly 200 GPa of steels, which matters for deflection-limited design and for bolt stiffness in flanged joints.
Available from 6 mm to 250 mm, in mill or cut lengths. Typical work is pump shafts, propeller shafts, subsea fasteners, valve trim, drill collars and non-sparking tools.
Common Applications of Monel K500 Round Bar
➡️ Machined shafts, spindles, valve stems, pump sleeves and pins for food, beverage, dairy and pharmaceutical equipment, where the passive chromium oxide film resists both product acids and caustic clean-in-place chemicals.
➡️ Fasteners, studs, bolts, threaded rod and anchor components produced from bar stock, chosen for corrosion resistance combined with the ductility needed for cold heading and thread rolling.
➡️ Chemical, water treatment and general process plant parts such as agitator shafts, flange blanks, nozzles and support components handling water, steam and mildly corrosive media free of significant chlorides.
➡️ Architectural and structural hardware including handrail stanchions, balustrade fittings, tension rods and bollards, where a bright ground or polished bar finish provides both appearance and low maintenance.
International Equivalent Grade for Monel K500 Round Bar
Standard
Country / Region
Grade
ASTM B865
USA
UNS N05500 (rod, bar and wire)
ASTM B564
USA
UNS N05500 (forgings)
DIN 17743
Europe / EU
2.4375 (NiCu30Al)
BS 3076
United Kingdom
NA 18
Technical Specification for Monel K500 Round Bar
Specification
Value
Unit
Material
Nickel alloy
-
Grade
Monel K500 / UNS N05500 / 2.4375
-
Product Form
Round bar / rod
-
Standard
ASTM B865
-
Diameter
6 - 250 (typical supply range)
mm
Length
3 - 6 (random), or cut to length
m
Manufacturing Process
Hot rolled or forged, solution annealed and age hardened
-
Production Route
EAF + AOD, with VIM or ESR remelt where specified
-
Surface Finish
Hot-rolled and pickled, peeled, turned, centreless ground, polished
-
Heat Treatment / Delivery Condition
Solution annealed approximately 980 C, aged approximately 595 C for 16 hours
-
Tolerance Standard
ASTM B865 permissible variations
-
Density
8.44 (typical)
g/cm3
Melting Range
1315 - 1350 (typical)
C
Thermal Conductivity at 20 C
17.5 (typical)
W/m.K
Coefficient of Thermal Expansion (20-100 C)
13.7 (typical)
um/m.C
Specific Heat (0-100 C)
419 (typical)
J/kg.K
Electrical Resistivity at 20 C
0.62 (typical)
uOhm.m
Modulus of Elasticity at 20 C
179 (typical)
GPa
Magnetic Properties
Reliably non-magnetic, Curie temperature well below ambient
-
Maximum Service Temperature
480 (typical, continuous)
C
Testing / Inspection Standard
ASTM E8 or ASTM A370 for mechanical testing, hardness verification
-
Certification / Inspection Documents
EN 10204 3.1 or 3.2 mill test certificate, NACE MR0175 compliance on request
-
Technical Specifications
Get the key technical specifications for Monel K500 Round Bar
Order to ASTM B865 under UNS N05500, with ASTM B564 covering forgings. Dimensional tolerances come from the permissible variations within B865.
The heat treatment is solution annealing at roughly 980 C followed by ageing at approximately 595 C for 16 hours with a controlled furnace cool. Ageing rate matters: cooling too quickly through the ageing range leaves the gamma prime under-developed and the strength short. Machining is normally carried out in the solution-annealed condition before ageing, since aged material is considerably harder and work hardens aggressively.
The hydrogen embrittlement issue deserves emphasis because it has caused real failures. Aged K500 in seawater under cathodic protection can absorb hydrogen and crack, and subsea fastener failures have been documented. Susceptibility rises with hardness and with the degree of ageing. NACE MR0175 / ISO 15156 imposes hardness limits, commonly around 35 HRC, and specifications for subsea bolting often go tighter still. Compliance must be requested on the order and confirmed on the certificate.
Two other properties are worth knowing. The alloy is reliably non-magnetic, unlike Monel 400 whose Curie temperature sits near ambient, which makes K500 the correct choice for magnetically sensitive assemblies. And it is non-sparking, which is why it appears in tools for explosive atmospheres.
Chemical Composition for Monel K500 Round Bar
Element
Symbol
Min
Max
Unit
Nickel
Ni
63.0
-
%
Copper
Cu
27.00
33.00
%
Aluminium
Al
2.30
3.15
%
Titanium
Ti
0.35
0.85
%
Iron
Fe
-
2.00
%
Manganese
Mn
-
1.50
%
Carbon
C
-
0.18
%
Silicon
Si
-
0.50
%
Sulfur
S
-
0.010
%
Chemical Composition
View the chemical composition and applicable material limits for Monel K500 Round Bar
Aluminium at 2.30-3.15% and titanium at 0.35-0.85% are the additions that separate this alloy from Monel 400, and everything that distinguishes K500 follows from them. During ageing they combine with nickel to precipitate a fine gamma prime phase throughout the matrix, and that precipitate roughly triples the proof strength while leaving the corrosion behaviour largely unchanged.
The same additions shift the Curie temperature well below ambient, which is why K500 is reliably non-magnetic while Monel 400 sits awkwardly near room temperature and may respond to a magnet.
Nickel at 63% minimum and copper at 27.00-33.00% form the base solid solution and carry the corrosion resistance, giving the same performance in seawater, brine, alkalis, reducing acids and hydrofluoric acid that makes Monel 400 valuable.
As with Monel 400, there is no chromium, so there is no passive film in the stainless sense and oxidising media such as nitric acid and ferric chloride attack the alloy rapidly.
Carbon up to 0.18%, iron up to 2.00%, manganese up to 1.50% and silicon up to 0.50% are controlled residuals. Sulphur is held tight at 0.010%, tighter than the 0.024% allowed in Monel 400, because sulphur is particularly damaging in an age-hardening alloy.
Mechanical Properties for Monel K500 Round Bar
Mechanical Property
Value
Unit
Tensile Strength, hot-worked and age-hardened, all sizes
965
MPa (minimum, ASTM B865)
Yield Strength 0.2% Proof, hot-worked and age-hardened, all sizes
690
MPa (minimum, ASTM B865)
Elongation in 50 mm, hot-worked and age-hardened
20
% (minimum)
Hardness, hot-worked and age-hardened
265
HBW or 27 HRC (maximum, ASTM B865)
Tensile Strength, cold-worked and age-hardened, 6.4 to 25.4 mm
1000
MPa (minimum)
Yield Strength 0.2% Proof, cold-worked and age-hardened, 6.4 to 25.4 mm
760
MPa (minimum)
Elongation, cold-worked and age-hardened, 6.4 to 25.4 mm
15
% (minimum)
Hardness, cold-worked and age-hardened, 6.4 to 25.4 mm
300
HBW or 32 HRC (maximum)
Tensile Strength, cold-worked and age-hardened, 76.2 to 101.6 mm
930
MPa (minimum)
Yield Strength 0.2% Proof, cold-worked and age-hardened, 76.2 to 101.6 mm
655
MPa (minimum)
Tensile Strength, annealed and age-hardened
895
MPa (minimum)
Yield Strength 0.2% Proof, annealed and age-hardened, 25.4 mm and over
585
MPa (minimum)
Hardness, unaged, hot-worked or cold-worked and annealed
185
HBW or 90 HRB (maximum)
Modulus of Elasticity
179
GPa (typical)
Mechanical Properties
Check the key mechanical properties and performance requirements of Monel K500 Round Bar
ASTM B865 requires the following of solution-annealed and aged UNS N05500 bar, all minima except hardness, which is quoted as a typical range. Testing follows ASTM E8 or ASTM A370.
At 965 MPa tensile minimum alongside 690 MPa minimum proof strength in the hot-worked and age-hardened condition, the alloy delivers roughly four times the proof strength of annealed Monel 400 while retaining the same corrosion behaviour. Note that B865 caps hardness rather than setting a floor: 265 HBW or 27 HRC maximum for hot-worked and aged material, rising to 300 HBW or 32 HRC for cold-worked and aged rounds up to 25.4 mm. That combination of strength with seawater and hydrofluoric acid resistance is what justifies its cost.
Elongation of 20% minimum is respectable for a material at this strength level.
The modulus of elasticity at 179 GPa is the same as Monel 400 and noticeably below the roughly 200 GPa of steels, which matters for deflection-limited design and for bolt stiffness in flanged joints.
Hardness is the property to watch for subsea service rather than strength, and B865 already caps it well below the NACE limit in most conditions. Susceptibility to hydrogen embrittlement under cathodic protection rises with hardness, so NACE MR0175 / ISO 15156 imposes limits, commonly around 35 HRC, and subsea bolting specifications frequently go tighter. A bar that meets ASTM B865 comfortably may still be unsuitable for a cathodically protected application, so the hardness result should be checked against the service requirement rather than against the standard alone.
Dimension / Sizes for Monel K500 Round Bar
Dimension / Size
Value
Unit
Diameter
6 - 250
mm
Standard Length
3 - 6 (random / mill lengths)
m
Custom Length
Cut to length available on request
-
Diameter Tolerance
Per ASTM B865 permissible variations, varies with size and finish
-
Length Tolerance
Per ASTM B865 or as agreed at order
-
Straightness Tolerance
Per ASTM B865 or as agreed at order
-
End Condition
Square cut, chamfered, or as ordered
-
Surface Finish
Hot-rolled and pickled, peeled, turned, centreless ground, polished
-
Available Size Range
6 - 250, larger diameters by forging on enquiry
mm
Cut-to-Length Availability
Available
-
Dimensional Standard
ASTM B865
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for Monel K500 Round Bar
Pricing for Monel K500 Round Bar
Round Bar Prices are generally quoted per kilograms or meters tonnes and can fluctuate with the global raw material and market prices. The final price will depend on a variety of factors, including the grade size, diameter, length, surface finish, the quantity and whether the bars are cut to length or in standard lengths.
For smaller quantities, we can also quote per metre or per piece basis once the required dimensions have been confirmed. Container-loads or orders that are larger in size are typically priced per tonne, based upon the specifications required and the supply conditions.
Please provide your desired dimensions, grades, length number, and end for a current quote including the lead time applicable and details for certification.
Pricing
Get current Monel K500 Round Bar pricing based on size, quantity, grade, finish, and delivery requirements.
Why Choose Us
Euro Steel Bars is an international distributor, stockist and exporter of stainless round steel bars that cover carbon, stainless alloy, special grades. We stock a variety of sizes and grades. We guarantee every order with mill test certificates as well as full quality-assurance documentation. Our name speaks to our roots: European-sourced materials that is backed by the certificates and rigor that buyers from Asia as well as the Gulf and Africa are looking for.
Each bar we deliver is accompanied by EN 10204 3.1 mill test certificates as well as complete documentation of quality, so what you receive corresponds to what’s written in the documents. We carry a selection of sizes and grades ready for transport, and cut length upon the request of customers, which results in quicker lead times, whether you’re ordering just a one-off spec or a complete project tonnage.
We operate an actual wholesale business that is that is supported with an internationally-operated supply chain therefore we are able to serve fabricators sourcing one grade the same way in the same way as an EPC contractor who is placing a large order. Our clients include manufacturers, fabricators EPC construction companies, engineers oil and gas projects as well as construction companies. we design our inventory as well as documentation to show what buyers need to bring projects forward.
Our customers trust us across Qatar, Oman, Bahrain, Kuwait, Jordan, Malaysia, Singapore, Thailand, Taiwan, Turkey, Italy and South Africa. If you’re looking to source an Gulf energy project, or a construction project within Southeast Asia, you get the same quality of certified material, the exact documentation, and the exact delivery procedure.
Frequently Asked Questions
What is Monel K500 Round Bar?
What is the difference between Monel 400 and K500?
Why is Monel K500 susceptible to hydrogen embrittlement?
What standard does Monel K500 Round Bar comply with?
What are the key mechanical properties of Monel K500 Round Bar?
Is Monel K500 magnetic?
Can Monel K500 be machined after ageing?
What sizes and lengths are available?
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