Monel 400 Fasteners Manufacturer & Exporter — ASTM F467 / F468, UNS N04400

Bolts, Nuts, Studs, Washers & Screws in Monel 400 — Zero MOQ, Ex-Stock in Mumbai, ISO 9001 & PED Certified

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Standards: ASTM F467, ASTM F468, ASME SF467, DIN 2.4360
Size Range: M2 – M160 metric / 1/4″ – 4″ imperial
Manufacturing: Hot Forging, Cold Forging, CNC Machining
Certification: ISO 9001:2015, PED 2014/68/EU, EIL Approved, NACE MR0175
MOQ: Zero — single pieces to bulk export

Table of Content

Introduction to Monel 400 Fasteners
ASTM F467, ASME SF 467 & ASTM B164 Specifications
Chemical Properties of Monel 400 Fasteners
Mechanical Properties of Alloy UNS N04400 Fasteners
400 Monel Alloy Fasteners Equivalent Grades
Available Types of Monel 400 Fasteners
Size Range & Dimensions
Manufacturing Standards & Thread Types
Monel 400 Fasteners Applications & Industries Served
Testing of Monel 400 Fasteners
Frequently Asked Questions

If you’ve ever had a stainless bolt seize or pit on a piece of marine or offshore equipment, you already understand why people ask us for Monel 400 fasteners. Monel 400 (UNS N04400, WNR 2.4360) is a nickel-copper alloy that keeps its strength and corrosion resistance in seawater, hydrofluoric acid, and chloride-heavy environments where stainless simply gives up. At Kalpataru Piping, we manufacture Monel 400 hex bolts, stud bolts, nuts, washers, socket head cap screws, and threaded rods to ASTM F467 and F468, in sizes from M2 to M160 metric or 1/4″ to 4″ imperial, with hot forging, cold forging, and CNC machining done in-house. We run zero MOQ — from a handful of pieces to full container loads — with most standard sizes ex-stock in Mumbai for 24-48 hour dispatch. Every fastener ships with EN 10204 3.1 mill test certificates, and we hold ISO 9001:2015, PED 2014/68/EU, and EIL approval. If you’re also sourcing Monel 400 flanges or Monel 400 pipes and tubes, these fasteners are built to the same UNS N04400 grade, so your bill of materials stays consistent end to end.

Product Overview: What Are Monel 400 Fasteners?

Monel 400 fasteners are bolts, nuts, studs, washers, and screws machined or forged from Monel 400 bar stock — the same nickel-copper alloy used across our pipe, flange, and fitting ranges. What makes them worth the extra cost over stainless is straightforward: they don’t gall as easily, they resist chloride stress-corrosion cracking almost entirely, and they hold up in hydrofluoric acid and sulfuric acid at moderate concentrations, which covers a lot of the chemical and marine environments where stainless fasteners quietly fail after a few years.

Chemical Composition of Monel 400 Fasteners

Element	Content (%)
Nickel (Ni)	63.00 min
Copper (Cu)	28.00 – 34.00
Iron (Fe)	2.50 max
Manganese (Mn)	2.00 max
Silicon (Si)	0.50 max
Carbon (C)	0.30 max
Sulphur (S)	0.024 max

Mechanical & Physical Properties

Property	Value
Tensile Strength (Annealed)	517 – 620 MPa (75 – 90 ksi)
Yield Strength (0.2%)	172 – 345 MPa (25 – 50 ksi)
Elongation	35 – 48%
Hardness	110 – 150 HB / 60 – 65 HRB
Operating Temperature Range	-34°C to 538°C (-30°F to 1000°F)
Typical Service Life	25 – 35 years in properly specified service
Density	8.80 g/cm³ (0.318 lb/in³)
Melting Point	1300 – 1350°C (2370 – 2460°F)

Available Types of Monel 400 Fasteners

We stock and supply the full range of standard hardware, plus precision-machined custom items. A quick rundown of what people usually order:

Hex Bolts: The most commonly specified fastener for marine, offshore, and chemical process piping. Available fully threaded (DIN 933) or partially threaded (DIN 931), in UNC, UNF, and metric thread forms from M6 to M160.
Stud Bolts: The primary fastener for flanged joints, supplied to ASME B16.5 flange dimensions in Class 150–2500 with 2B thread tolerance and chamfered ends — see our Monel 400 Stud Bolt dimension table below.
Heavy Hex Bolts & Nuts: Larger across-flats dimensions for greater bearing area on heavy structural and pressure-vessel connections.
Eye Bolts & U-Bolts: DIN 580/582 eye bolts for rigging and lifting, and U-bolts for pipe clamping and structural support in marine and chemical environments.
Lock Nuts, Nylon & Wing Nuts: DIN 985 nyloc nuts for vibration-resistant joints on rotating machinery, plus wing nuts for tool-free assembly and disassembly.
Socket Head Cap Screws: ASME B18.3 Allen-key drive screws for confined-space installations on valve bodies, instrument fittings, and compact assemblies.
Threaded Rods: Fully threaded rods (DIN 975) and stud-length rods to ASME B16.5 for flange joint assembly in piping systems.

Monel 400 Stud Bolts — Sample ASME B16.5 Flange Dimensions (Class 150, RF)

Pipe Size (NPS)	No. of Bolts	Bolt Diameter	Stud Length
1/2″	4	1/2″	2 3/4″
2″	4	5/8″	3 1/4″
4″	8	5/8″	3 1/2″
8″	8	3/4″	4 1/4″
12″	12	7/8″	4 3/4″

Standards & Dimensional References

Standard	Fastener Type	Coverage
DIN 931 / 933	Hex Bolts (partial / full thread)	General hex head bolts, most common bolt standard
DIN 934	Hex Nuts	Standard hex nuts, all metric sizes
DIN 912	Socket Head Cap Screws	Allen key drive cap screws
DIN 975 / 976	Threaded Rods / Studs	Fully threaded rods and stud bolts
DIN 125 / 127	Washers (plain / spring)	Flat and spring lock washers
DIN 985 / 6923	Nyloc Nuts / Flange Nuts	Self-locking and flange-bearing nuts
DIN 580 / 582	Eye Bolts / Eye Nuts	Lifting and rigging applications

Applications & Industries

Oil & Gas Offshore Platforms: wellhead fasteners, Christmas tree bolting, subsea manifold hardware, riser clamps, and sour gas service components meeting NACE MR0175 / ISO 15156.
Marine Shipbuilding: seawater piping flanges, heat exchanger bolting, propulsion system fasteners, deck hardware, and salt water tank internals.
Desalination Plants: MSF and RO seawater intake bolting, brine heater fasteners, and high-pressure membrane frame hardware.
Chemical & HF Acid Service: HF acid alkylation unit fasteners, chlorine production equipment bolting, and caustic soda system hardware.
Refineries & Petrochemical: crude petroleum still fasteners and gas scrubbing tower bolting for EIL-approved refinery projects.
Power Generation: condenser fasteners, boiler feedwater heater bolting, and steam turbine component studs.
For the pipe, flange, and fitting components these fasteners connect to, see our Monel 400 pipes and tubes, Monel 400 flanges, and Monel 400 forged fittings pages.

Why Choose Kalpataru Piping

We’ve been machining and forging nickel alloy fasteners long enough to know that most delays in this business come from suppliers who don’t actually stock what they list. We keep standard M6–M56 sizes ex-stock in our Mumbai warehouse for 24–48 hour dispatch, and everything else — up to M100 diameter, 1,500 mm length, with head marking, thread locking, or coating — is machined in-house rather than farmed out. If you want the full picture of how we’re set up, our About Us page has it.

Zero MOQ, ex-stock — no minimum order required, from single pieces to bulk tonnage
In-house CNC machining up to M100 diameter and 1,500 mm length, with custom marking, thread locking, and coating
Complete documentation — EN 10204 3.1 MTC, PMI certificates, TPI reports, and full traceability for QA/QC compliance
Export-grade packaging and a proven logistics network to UAE, Saudi Arabia, Qatar, UK, Germany, USA, Singapore, Australia, and 40+ countries
Transparent, competitive pricing with bulk discounts and long-term contract rates direct from the manufacturer — no intermediary markup
A technical team that will walk you through Monel 400 vs K500 selection, not just take the order

Monel 400 vs Monel K500 Fasteners — Which Grade Do You Need?

This is the single most common material question we get on nickel-copper fasteners, and it comes down to load and cost. Monel 400 covers the vast majority of chemical, marine, and general corrosion-resistant fastening needs at a lower price point. Monel K500 is age-hardened for roughly 30–50% higher cost and earns its keep on shafting, pump components, valve stems, and other high-load structural or wear applications.

Property	Monel 400 (UNS N04400)	Monel K500 (UNS N05500)
Tensile Strength	517 – 620 MPa	900 – 1100 MPa (age-hardened)
Yield Strength	172 – 345 MPa	620 – 790 MPa
Heat Treatment	Not required	Requires age hardening
Relative Cost	Lower	30–50% higher
Best For	Chemical, marine, acid service, flanged joints, general corrosion-resistant fastening	Marine shafting, pump components, valve stems, high-load structural fasteners, wear applications

If your specification doesn’t call for elevated strength or wear resistance, Monel 400 is the more cost-effective corrosion-resistant choice. See our Monel K500 fasteners page for the age-hardened, high-strength option, or our Monel 400 vs Inconel 625 fasteners guide if you’re comparing across alloy families entirely.

Monel 400 Fasteners vs Stainless Steel — Performance Comparison

The lifecycle cost argument for specifying Monel 400 over stainless is straightforward in marine and acid service, where SS304 and SS316 fasteners fail by pitting and stress corrosion cracking within 5–15 years.

Property	Monel 400	SS 304	SS 316
Seawater Resistance	Excellent	Poor (pitting)	Fair (pitting)
Hydrofluoric Acid (all concentrations)	Excellent	Poor	Poor
Sulfuric Acid (dilute)	Excellent	Good	Good
Chloride Stress Corrosion Cracking	Immune	Susceptible	Resistant
Relative Cost	Higher upfront	Lower	Moderate
Service Life in Marine Service	25–35 years	5–10 years	10–15 years

For a straight stainless alternative where the environment allows it, see our stainless steel fasteners range.

Manufacturing Process & Quality Control

Small fasteners (M6–M24) are cold forged, larger sizes (M24–M100) are hot forged, and anything needing tight tolerances or a non-standard head style goes through CNC machining. We work in UNC, UNF, BSF, metric, BUN, NPT, and NPTF thread types, with hex, Phillips, slotted, six-lobe, or socket (Allen) drive heads depending on the application.

Before dispatch, every batch goes through non-destructive and destructive testing: ultrasonic and liquid penetrant testing, positive material identification, and full visual/dimensional inspection as standard, plus tensile, yield, hardness, and — on request — Charpy impact testing per heat. Chemical analysis is carried out in an NABL-accredited lab. Every order ships with an EN 10204 3.1 mill test certificate and ASTM/ASME mill certification; third-party inspection through Bureau Veritas, SGS, or Lloyd’s, and NABL-approved lab reports, are available on request.

Certificates & Documentation

Certificate Type	Standard	Availability
Manufacturer’s Test Certificate (MTC)	EN 10204 3.1	Standard with all orders
Mill Test Certificate	ASTM / ASME	Standard with all orders
Third-Party Inspection (TPI)	Bureau Veritas / SGS / Lloyd’s	On request
NABL Approved Lab Reports	NABL Accredited	On request
Heat / Lot Traceability Report	—	Standard with all orders

Certifications & Approvals

Certification	What It Covers
ISO 9001:2015	Quality management system governing manufacturing, inspection, and dispatch
PED 2014/68/EU	Pressure Equipment Directive compliance for fasteners supplied into EU pressure systems
EIL Approved Manufacturer	Pre-qualification credential for refinery and petrochemical project procurement in India
NACE MR0175 / ISO 15156	Qualified for sour service oil & gas, wellhead, and subsea fastener applications
EN 10204 3.1 MTC	Third-party witnessed material test certificates, standard with every shipment
NABL Approved Lab Reports	Chemical, mechanical, and hardness testing from NABL-accredited labs, on request

Frequently Asked Questions

What is the difference between Monel 400 and Monel K500 fasteners?

Monel 400 (UNS N04400) is the less expensive option and the standard choice for marine, chemical, and acid service. Monel K500 (UNS N05500) is age-hardened for tensile strengths of 900–1100 MPa, which makes sense for high-load applications like marine shafting, pump parts, and valve stems — but it typically costs 30–50% more than Monel 400.

What standards govern Monel 400 fasteners?

Bolts, screws, and studs are made to ASTM F468 (or ASME SF467), while nuts follow ASTM F467. You’ll also see the same material referred to as UNS N04400, WNR/DIN 2.4360, or by the trade names Nicorros LC, Monel 400, or Phyweld 400.

What is the operating temperature range of Monel 400 fasteners?

Roughly -34°C to 538°C (-30°F to 1000°F) for continuous service, which covers the vast majority of process, marine, and chemical applications.

Can Monel 400 fasteners be used in seawater service?

Yes — this is genuinely one of the best alloys available for seawater. It resists chloride stress corrosion cracking almost completely, which is exactly where stainless fasteners tend to fail.

What certifications does Kalpataru Piping hold on Monel 400 fasteners?

Yes — this is genuinely one of the best alloys available for seawater. It resists chloride stress corrosion cracking almost completely, which is exactly where stainless fasteners tend to fail.

What is the minimum order quantity for Monel 400 fasteners?

We run a zero-MOQ policy. Standard M6–M56 sizes are ex-stock in Mumbai for 24–48 hour dispatch, whether you need five pieces or five tonnes.

What is the HS code for Monel 400 fasteners?

Generally 7318.15.00, though it’s worth confirming the exact classification with your customs broker since it can vary slightly by destination country.

Are Monel 400 fasteners suitable for hydrofluoric (HF) acid service?

Yes, across all concentrations — this is actually one of the few materials that holds up reliably in HF acid, which is why it’s specified so heavily in alkylation units.

What's an indicative price range for Monel 400 fasteners?

As a rough guide, Monel 400 hex bolts run from around $5.50–$7.50/piece for M6–M12 up to $12–$25/piece for M16–M24, with nuts, washers, and stud bolts priced separately. Actual pricing depends on current LME nickel pricing, order quantity, and specification, so treat any published figure as indicative and confirm current pricing with our sales team.

Should I choose Monel 400 or Inconel 625 fasteners?

Monel 400 is generally the more cost-effective choice for chloride and moderate-acid service; Inconel 625 steps in when you need resistance to a wider range of oxidizing and reducing acids, or higher-temperature strength. If you’re not sure which your application needs, tell us the service conditions and we’ll recommend the right grade.

Ready to Order Monel 400 Fasteners That Won't Let You Down?

Send us your size, quantity, and standard, and we’ll come back with real pricing and a real lead time — zero MOQ, ISO 9001 and PED certified, EIL approved. Completing a full flanged joint? Check our Monel 400 flanges and Monel 400 buttweld fittings pages to complete the bill of materials in one order.