Monel K500 FlangesUNS N05500 · Manufacturer, trader & exporter, India
Also sold as Alloy K-500 · UNS N05500 · W.Nr 2.4375 · Age-hardened Monel
Monel K500 flanges are supplied with dimensions to ASME B16.5 (½"–24", Class 150–2500) or ASME B16.47 for larger sizes. The finished flange specification for Monel K500 is project / purchase specification dependent; ASTM B865 covers UNS N05500 bar, rod, wire, forgings and forging stock; it is not asserted here as the finished flange specification. It is a age-hardenable nickel–copper alloy with aluminium and titanium, chosen for high-strength pump shafts, bolting and springs in seawater. Kanak Steel & Engineering Co. manufactures, trades and exports it from Mumbai; EN 10204 3.1 or 3.2 certificates are available on request / as specified in the PO. Markets we have supplied to include Oman, UAE, Saudi Arabia, Brazil, Argentina, Spain and Chile (India is the home market).
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- NACE MR0175 on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Monel K500 Flanges?
Monel K500 flanges is an age-hardenable nickel–copper alloy with aluminium and titanium supplied as flanges (UNS N05500); the finished flange specification is project / purchase specification dependent. Buyers specify it for high-strength pump shafts, bolting and springs in seawater. It is also sold as Alloy K-500, UNS N05500, W.Nr 2.4375.
- What it is
- Age-hardenable nickel–copper alloy with aluminium and titanium
- Finished flange specification
- Project / purchase specification dependent
- Dimensions
- ASME B16.5 · B16.47 · EN 1092-1
- Classes
- 150 · 300 · 600 · 900 · 1500 · 2500
- Facing
- RF · FF · RTJ
- Best at
- High-strength pump shafts, bolting and springs in seawater
Monel K500 Flanges Specification & Sizes
| Finished flange specification | As specified — state on purchase order |
|---|---|
| Material relationship | ASTM B865 covers UNS N05500 bar, rod, wire, forgings and forging stock; it is not asserted here as the finished flange specification |
| Dimensional standards | ASME B16.5 (½"–24") · B16.47 Series A / B (26"–60") · B16.36 orifice · B16.48 line blanks · EN 1092-1 |
| Pressure classes | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | Raised face (RF) · flat face (FF) · ring type joint (RTJ) · tongue & groove |
| Bore | To match the pipe schedule — specify it on the order |
| Types | Weld neck flange · Slip-on flange · Blind flange · Socket weld flange · Threaded flange · Lap joint flange · Long weld neck flange · Orifice flange · Spectacle blind · Reducing flange · Ring type joint flange · Expander flange · Anchor flange · Swivel ring flange |
| Testing | PMI · dimensional · UT of forgings · IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
Monel K500 Flange Pressure–Temperature Rating
The class is not a pressure: the allowable pressure for K500 flanges comes from the ASME B16.5 table for its material group, and falls as temperature rises (how ratings work). The finished flange specification is project / purchase specification dependent, so its B16.5 material group is not named here; confirm the specification before choosing the class.
Take the actual pressures from the B16.5 rating table for your material’s group. A class is not a project pressure rating — your piping class sheet and design conditions govern.
Bolting & Gaskets for K500 Flanges
For Monel K500 flanges the usual bolting is B7 (coated), B8M or nickel-alloy studs in Monel K500 (bar to ASTM B865, where applicable), as the project specifies — see Monel K500 fasteners. Spiral-wound gaskets for this service usually use a winding in the same or a higher alloy, so the gasket does not corrode first. Facing and gasket options are compared in the flange guide.
Monel K500 Flanges Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel (+Co) | As specified |
| Copper | As specified |
| Aluminium | As specified |
| Titanium | As specified |
| Iron | As specified |
| Manganese | As specified |
| Carbon | As specified |
| Silicon | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM B865 for UNS N05500.
Monel K500 Flanges Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM B865 for UNS N05500 — Age-hardened bar.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8.44 g/cm³ |
| Melting range | 1315 – 1350 °C |
| Magnetic | Non-magnetic to about −100 °C |
Monel K500 Equivalent Grades
Monel K500 flange dimensions — ASME B16.5 Class 150 & 300
Outside dimensions depend only on size and class, not on the alloy, so K500 flanges bolt to any B16.5 flange of the same size and class. Values in mm; thickness excludes the 1.6 mm raised face.
| NPS | Cl 150 OD | Cl 150 thickness | Cl 150 bolt circle | Cl 150 bolts | Cl 300 OD | Cl 300 thickness | Cl 300 bolt circle | Cl 300 bolts |
|---|---|---|---|---|---|---|---|---|
| ½" | 90 | 9.6 | 60.3 | 4 × ½" | 95 | 12.7 | 66.7 | 4 × ½" |
| 1" | 110 | 12.7 | 79.4 | 4 × ½" | 125 | 15.9 | 88.9 | 4 × ⅝" |
| 1½" | 125 | 15.9 | 98.4 | 4 × ½" | 155 | 19.1 | 114.3 | 4 × ¾" |
| 2" | 150 | 17.5 | 120.7 | 4 × ⅝" | 165 | 20.7 | 127.0 | 8 × ⅝" |
| 3" | 190 | 22.3 | 152.4 | 4 × ⅝" | 210 | 27.0 | 168.3 | 8 × ¾" |
| 4" | 230 | 22.3 | 190.5 | 8 × ⅝" | 255 | 30.2 | 200.0 | 8 × ¾" |
| 6" | 280 | 23.9 | 241.3 | 8 × ¾" | 320 | 35.0 | 269.9 | 12 × ¾" |
| 8" | 345 | 27.0 | 298.5 | 8 × ¾" | 380 | 39.7 | 330.2 | 12 × ⅞" |
| 10" | 405 | 28.6 | 362.0 | 12 × ⅞" | 445 | 46.1 | 387.4 | 16 × 1" |
| 12" | 485 | 30.2 | 431.8 | 12 × ⅞" | 520 | 49.3 | 450.8 | 16 × 1⅛" |
Full chart: ASME B16.5 flange dimensions.
Six-digit Harmonized System heading (nickel alloy, chapter 75). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Monel K500 Flanges with PMI
Positive material identification with a handheld XRF gun confirms the alloy on the piece itself, in seconds, before it is cut or welded. Monel K500 is most often mixed up with Monel 400 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen; those come from the mill certificate or optical emission (OES) testing. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | Monel K500 | Monel 400 |
|---|---|---|
| Nickel | As specified | As specified |
| Copper | As specified | As specified |
| Titanium | As specified | — |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
Monel K500 Flanges Price — What Decides It
Two quotes for "K500 flanges" can differ by 20% and both be fair. We quote K500 flanges per kg for full sizes and per piece for cut sizes. These six things move the price per kg, so you can compare offers like for like.
Monel K500 flanges by type
Monel K500 Flanges Applications
Monel K500 is specified when the cheaper grade will not survive the service but a higher alloy would be more than the job needs. These are the jobs our buyers use it for.
Monel K500 Flanges vs 400, 718 and 2507
| Grade | Flanges standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Monel 400 | ASTM B564 | — | Seawater, hydrofluoric acid and marine service |
| Inconel 718 | project / purchase specification dependent | — | Very high strength at temperatures up to about 650 °C |
| Monel K500 | project / purchase specification dependent | — | High-strength pump shafts, bolting and springs in seawater |
| Super Duplex 2507 | ASTM A182 F53 | ≈ 42 | Seawater and high-chloride service where strength also matters |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Monel K500 Corrosion Resistance — Element by Element
Each alloying addition has a job. Knowing which one protects against your medium is the quickest way to judge whether K500 fits.
Aluminium and titanium let K500 be age-hardened to about three times the strength of Monel 400.
Keeps the seawater corrosion resistance of Monel 400.
Chosen where a part needs strength and seawater resistance together.
In sour service, check hardness limits in NACE MR0175 before specifying.
How your K500 flanges order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI can be arranged depending on product and requirements, as specified in the PO.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked as specified in the PO.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Standards on this page
Welding & Fabricating Monel K500 Flanges
Monel K500 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ERNiCu-7 (non-ageing) |
|---|---|
| Over-alloyed filler | Weld in the annealed condition, then age |
| Preheat | Not required; keep interpass temperature low |
| Cutting | Thermal or abrasive cutting; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance.
How to Order Monel K500 Flanges: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Flange type and dimensional standard (B16.5 / B16.47 / EN 1092-1)
- Size, pressure class and facing
- Bore / schedule for weld neck and socket weld flanges
- Material standard and grade marking
- Certificate type and extra tests
- Delivery port, Incoterm and required date
Monel K500 flanges — questions buyers ask
Is Monel K500 the same as Alloy K-500?
Alloy K-500, UNS N05500, W.Nr 2.4375 are names used for Monel K500 (W.Nr / EN numbers and older UNS variants are the closest designations; their limits can differ slightly, so specify the UNS number and ASTM grade on the order). Whichever name is on the enquiry, the finished flange specification is project / purchase specification dependent.
Which standard covers Monel K500 flanges?
The finished flange specification for Monel K500 is project / purchase specification dependent, so none is named here. Dimensions follow ASME B16.5 for ½"–24" and ASME B16.47 for 26" and above; state the flange specification your project requires on the order.
What pressure can a Monel K500 Class 300 flange take?
It depends on temperature and on the ASME B16.5 material group of the finished flange specification, which is project / purchase specification dependent for this grade. Confirm the specification first, then read the Class 300 column of that group's rating table at your design temperature.
Which bolts should I use with Monel K500 flanges?
Usually B7 (coated), B8M or nickel-alloy studs in Monel K500 (bar to ASTM B865, where applicable), as the project specifies. In corrosive or sour service the bolting material is set by the project specification.
Can a Monel K500 flange be welded to a different pipe material?
Yes — a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel. Weld neck bores must match the mating pipe schedule.
Can Monel K500 flanges be supplied to NACE MR0175?
Monel K500 (UNS N05500) can be supplied for sour service when the PO specifies NACE MR0175 / ISO 15156; acceptability depends on the material condition, hardness and the environmental limits in that standard, which the purchaser must confirm for the application.
Monel K500 or Super Duplex 2507 — which should I choose?
Monel K500 is chosen for high-strength pump shafts, bolting and springs in seawater. Super Duplex 2507 is the step up when you need more pitting resistance or strength. See the comparison table on this page, or ask us with your process conditions.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026