Monel 400 FastenersUNS N04400 · Manufacturer, trader & exporter, India
Also sold as Alloy 400 · UNS N04400 · W.Nr 2.4360 · Nicorros
Monel 400 fasteners — stud bolts, hex bolts, nuts and washers — available in this alloy. ASTM F468 (N04400) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B164 bar where applicable, subject to the purchase specification. Dimensions to ASME B18 where applicable, or your drawing. State the finished fastener specification your project requires on the order. It is a nickel–copper alloy, chosen for seawater, hydrofluoric acid and marine service. 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
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Monel 400 Fasteners?
Monel 400 fasteners is a nickel–copper alloy supplied as fasteners (UNS N04400). ASTM F468 (N04400) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B164 bar where applicable, subject to the purchase specification. Buyers specify it for seawater, hydrofluoric acid and marine service. It is also sold as Alloy 400, UNS N04400, W.Nr 2.4360.
- What it is
- Nickel–copper alloy
- Material
- ASTM F468 (N04400) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B164 bar where applicable, subject to the purchase specification
- Feedstock (bar)
- ASTM B164, where applicable
- Dimensions
- ASME B18.2.1 · B18.2.2 · B18.31.2
- Threads
- UNC · UN-8 · metric
- Sizes
- M10 – M64 · ½" – 4"
- Best at
- Seawater, hydrofluoric acid and marine service
Monel 400 Fasteners Specification & Sizes
| Material | ASTM F468 (N04400) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B164 bar where applicable, subject to the purchase specification |
|---|---|
| Material / feedstock | ASTM B164 — a bar specification, where applicable; it covers the bar, not the finished fastener |
| Manufacturing route | By type: bolts, studs, cap screws and nuts may be machined from bar, where applicable; threaded rod, U-bolts, eye bolts, anchor and foundation bolts are route-dependent; washers not asserted — all to the purchase specification or project drawing |
| Dimensional standards | ASME B18.2.1 (bolts) · B18.2.2 (nuts) · B18.31.2 (studs) · DIN 931 / 933 / 934 (legacy DIN) |
| Types | Stud bolt · Hex bolt · Heavy hex nut · Hex nut · Washer · Threaded rod · U-bolt · Eye bolt · Anchor bolt · Foundation bolt · Socket head cap screw · Machine screw |
| Threads | UNC, UN-8 and metric coarse |
| Coating | Plain · PTFE on request |
| Documents | EN 10204 3.1 |
Monel 400 Stud Bolts: Grade & Nut Pairing
Monel 400 studs and nuts may be machined from ASTM B164 bar, where applicable; the finished fastener specification is to the purchase specification or project drawing, and the nut is usually the same alloy.
Torque (T = K × F × d), stud length and coatings are covered in the fasteners guide.
| Galling | Stainless and nickel-alloy threads gall — always use anti-seize, and avoid high-speed tightening |
|---|---|
| Coatings | Usually supplied plain; PTFE coating on request to ease tightening |
| Marking | Grade symbol and maker's mark on each stud end and nut, as the standard requires |
| Certificates | EN 10204 3.1 for the bar heat; mechanical test reports on the finished bolts on request |
Monel 400 Fasteners Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel (+Co) | As specified |
| Copper | As specified |
| Iron | As specified |
| Manganese | As specified |
| Carbon | As specified |
| Silicon | As specified |
| Sulphur | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM B127 for UNS N04400.
Monel 400 Fasteners 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 B127 for UNS N04400 — Annealed plate.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8.8 g/cm³ |
| Melting range | 1300 – 1350 °C |
| Magnetic | Slightly magnetic at room temperature |
Monel 400 Equivalent Grades
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 400 Fasteners 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 400 is most often mixed up with Monel K500 — 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 400 | Monel K500 |
|---|---|---|
| Nickel | As specified | As specified |
| Copper | As specified | As specified |
| Titanium | — | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
Monel 400 fasteners by type
Monel 400 Fasteners Applications
Monel 400 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 400 Fasteners vs 625, 2507 and 316L
| Grade | Fasteners standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Monel 400 | ASTM F468 (N04400) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B164 bar where applicable, subject to the purchase specification | — | Seawater, hydrofluoric acid and marine service |
| SS 316 / 316L | ASTM A193 B8M · A194 8M | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| Super Duplex 2507 | ASTM A1082 (S32750) where specified for applicable duplex bolts, studs, cap screws and nuts; for other types, material may be supplied to ASTM A276 / A479 bar where applicable, subject to the purchase specification | ≈ 42 | Seawater and high-chloride service where strength also matters |
| Inconel 625 | ASTM F468 (N06625) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B446 bar where applicable, subject to the purchase specification | ≈ 51 | Seawater, high strength and high temperature in one alloy |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Monel 400 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 400 fits.
Very low corrosion rates in flowing seawater and brackish water.
One of the few alloys that handles hydrofluoric acid in all concentrations (air-free).
Resists caustic alkalis and chloride stress-corrosion cracking.
Avoid nitric acid, aerated ammonia and oxidising salts.
How your 400 fasteners 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 400 Fasteners
Monel 400 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ERNiCu-7 (AWS A5.14) |
|---|---|
| Over-alloyed filler | ENiCu-7 electrode |
| 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. See also 400 fittings and 400 flanges for the matching pipe-system parts.
How to Order Monel 400 Fasteners: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Fastener type, size and length
- Thread form
- Material and marking
- Quantity in sets
- Certificate type
- Delivery port and date
Monel 400 fasteners — questions buyers ask
Is Monel 400 the same as Alloy 400?
Alloy 400, UNS N04400, W.Nr 2.4360 are names used for Monel 400 (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, fasteners: ASTM F468 (N04400) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.).
Why use Monel 400 bolts instead of B7 carbon steel?
On Monel 400 flanges in corrosive service, carbon-steel bolts corrode first. Matching-alloy bolting avoids galvanic corrosion and bolt failure.
What nut goes with Monel 400 stud bolts?
Usually a heavy hex nut in the same Monel 400 alloy — it may be machined from ASTM B164 bar, where applicable; finished requirements are to the purchase specification or project drawing.
How do I stop Monel 400 bolts galling?
Use an anti-seize compound on threads and nut faces, tighten at moderate speed, and do not reuse galled nuts.
Monel 400 or SS 316 / 316L — which should I choose?
Monel 400 is chosen for seawater, hydrofluoric acid and marine service. SS 316 / 316L 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