Monel 400 FastenersASTM B164 UNS N04400 · Manufacturer, stockist & exporter, India
Also sold as Alloy 400 · UNS N04400 · W.Nr 2.4360 · Nicorros
Monel 400 fasteners — stud bolts, hex bolts, nuts and washers — are made from ASTM B164 bar stock to ASME B18 dimensions. It is a nickel–copper alloy, chosen for seawater, hydrofluoric acid and marine service. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on every heat
- NACE MR0175 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 to ASTM B164 (UNS N04400). 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
- Bar stock
- ASTM B164
- 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 B164 |
|---|---|
| Dimensional standards | ASME B18.2.1 (bolts) · B18.2.2 (nuts) · B18.31.2 (studs) · DIN 931 / 933 / 934 |
| 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 are machined from ASTM B164 bar; 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
| Element | Weight % |
|---|---|
| Nickel (+Co) | 63.0 min |
| Copper | 28.0 – 34.0 |
| Iron | 2.5 max |
| Manganese | 2.0 max |
| Carbon | 0.3 max |
| Silicon | 0.5 max |
| Sulphur | 0.024 max |
Monel 400 Fasteners Mechanical Properties
| Annealed plate | Value |
|---|---|
| Tensile strength | 480 MPa · 70 ksi |
| Yield strength 0.2% | 195 MPa · 28 ksi |
| Elongation | 35% |
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
Values follow ASTM B127 for UNS N04400. Always check against the edition named on your purchase order.
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. We PMI-test nickel alloys as standard and any grade on request.
| Element | Monel 400 | Monel K500 |
|---|---|---|
| Nickel | 63.0 min | 63.0 min |
| Copper | 28.0 – 34.0 | 27.0 – 33.0 |
| Titanium | residual | 0.35 – 0.85 |
| Iron | 2.5 max | 2.0 max |
| Manganese | 2.0 max | 1.5 max |
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 B164 | — | 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 A276 / A479 | ≈ 42 | Seawater and high-chloride service where strength also matters |
| Inconel 625 | ASTM B446 | ≈ 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 and material is PMI-tested before processing.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
- 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.
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 for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiMonel 400 fasteners — questions buyers ask
Is Monel 400 the same as Alloy 400?
Yes. Alloy 400, UNS N04400, W.Nr 2.4360 all refer to the same material, and fasteners is ordered to ASTM B164 whichever name is on the enquiry.
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?
A heavy hex nut machined from the same Monel 400 bar (ASTM B164), unless the project specifies otherwise.
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