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Hastelloy C276 Washers Manufacturer & Exporter in India

Explore Hastelloy C276 Washers Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-200

Min Temp

1100

Max Temp

🌡

1100

Suitable for continuous service up to approximately 1100°C under typical operating conditions.

⚡

800

Typical tensile strength around 800 MPa depending on product form and heat treatment.

🛡

Excellent

Excellent corrosion resistance in a wide range of industrial environments.

⚖

8.9

Typical density is approximately 8.9 g/cm³.

Product Overview

What are Hastelloy C276 Washers?

Hastelloy C276 washers are nickel-molybdenum-chromium alloy fastener components manufactured from UNS N10276 bar or plate stock conforming to ASTM B574 and ASTM B575. The alloy’s exceptional corrosion resistance stems from its high molybdenum content (15-17%) and tungsten addition (3-4.5%), which together suppress pitting, crevice corrosion, and stress corrosion cracking across a broad range of aggressive media.

With a PREN exceeding 70, Hastelloy C276 washers outperform all standard stainless steel and duplex grades in oxidising and reducing acid environments. They are specified under NACE MR0175/ISO 15156 for sour-service flange assemblies, chemical reactor closures, and offshore process piping where standard washers fail within months of service.

Quick Specifications

MaterialHastelloy C276
UNS NumberN10276
DIN Number2.4819
Material StandardASTM B574 / ASTM B575
Washer Standard (Metric)DIN 125 / DIN 9021 / ISO 7089
Washer Standard (Inch)ASME B18.21.1 / ASME B18.22.1
Types AvailableFlat, Spring, Lock, Fender, Taper, Dock
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength690 MPa (100 ksi) min
Yield Strength283 MPa (41 ksi) min
HardnessMax 35 HRC / 241 HB
? All material certified by NABL-accredited laboratory. PMI available on request.

Complete the Fastener Set

Other Hastelloy C276 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Hastelloy C276 fastener range from certified nickel-molybdenum-chromium superalloy bar stock, including Hastelloy C276 Bolts, Hastelloy C276 Nuts, Hastelloy C276 Screws, Hastelloy C276 Studs, and Hastelloy C276 Threaded Rods. All Hastelloy C276 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Hastelloy C276 Bolts
Hastelloy C276 Nuts
Hastelloy C276 Screws
Hastelloy C276 Studs
Hastelloy C276 Threaded Rods

Technical Data

Hastelloy C276 Washers Dimensions, Sizes & Thread Standards

Hastelloy C276 Washers are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 125 (flat washers) / DIN 9021 (large OD washers) / ISO 7089. Custom OD and thickness available. Inch dimensions per ASME B18.21.1 and ASME B18.22.1. All Hastelloy C276 washers dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Flat Washer Dimensions - Metric (DIN 125 / ISO 7089)

Bolt Size (M)ID (mm)OD (mm)Thickness (mm)Large OD DIN 9021 (mm)
M66.4121.618
M88.4161.624
M1010.5202.030
M1213.0242.537
M1617.0303.050
M2021.0373.060
M2425.0444.072
M3031.0564.092
M3637.0665.0110
M4243.0787.0130
M4850.0928.0150
M5658.01059.0175
M6466.01159.0200
M7274.012510.0220
M8082.014012.0250
M100104.017514.0310

Dimensional & Material Standards

StandardCoversSystem
DIN 125Flat washers, normal seriesMetric
DIN 9021Flat washers, large OD seriesMetric
ISO 7089Plain washers, normal seriesMetric
ISO 7093Plain washers, large seriesMetric
ASME B18.21.1Lock washersInch
ASME B18.22.1Plain washersInch
ASME B16.5Flange assembly washersInch
Material StandardRequirement
ASTM B574Bar/rod - UNS N10276
ASTM B575Plate/sheet - UNS N10276
ASTM F467Fastener mechanical properties
NACE MR0175Sour service =35 HRC
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Hastelloy C276 Chemical Composition

Hastelloy C276 Washers derive their exceptional acid corrosion resistance from a precisely controlled nickel-molybdenum-chromium composition per ASTM. High molybdenum and tungsten content suppresses pitting and reducing-acid attack; ultra-low carbon (0.01% max) eliminates sensitization risk in welded assemblies. Full elemental composition is certified in the EN 10204 MTC supplied with every Hastelloy C276 washers order from RealBolt.

Chemical Composition per ASTM B574 / ASTM B575

ElementComposition (%)
Nickel (Ni)Balance (approx. 57% min)
Molybdenum (Mo)15.0-17.0%
Chromium (Cr)14.5-16.5%
Iron (Fe)4.0-7.0%
Tungsten (W)3.0-4.5%
Cobalt (Co)2.5% max
Manganese (Mn)1.0% max
Vanadium (V)0.35% max
Silicon (Si)0.08% max
Carbon (C)0.01% max
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Hastelloy C276 Alloy Composition Matters for Washers

Mo (15–17%) — Reducing Acid & Crevice Resistance
The high molybdenum content gives Hastelloy C276 washers outstanding resistance to reducing acids including hydrochloric, sulfuric, and phosphoric acid. Crevice corrosion under the washer bearing face — a common failure mode for stainless steel — is effectively eliminated.
W (3–4.5%) — Pitting Resistance Enhancement
Tungsten works synergistically with molybdenum to push the PREN above 70, providing immunity to chloride pitting in seawater and process brines even at elevated temperatures. This makes C276 washers the preferred choice for offshore and marine flange assemblies.
Ultra-Low Carbon (0.01% max) — Sensitisation-Free
The extremely low carbon ceiling prevents carbide precipitation at grain boundaries during welding or elevated-temperature service. Hastelloy C276 washers retain full corrosion resistance in heat-affected zones without requiring post-weld annealing, simplifying fabrication and inspection.

Fastener Performance

Hastelloy C276 Washers Mechanical Properties & Torque & Proof Load Reference

The table below lists mechanical properties and proof load reference for Hastelloy C276 Washers per ASTM. Hastelloy C276 washers achieve 800 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Washer Bearing Load Reference - Flat Washers (DIN 125)

Washer SizeID (mm)OD (mm)Thickness (mm)Max Bearing Load (kN)
M1213.0242.528
M1617.0303.052
M2021.0373.082
M2425.0444.0118
M3031.0564.0190
M3637.0665.0278
M4243.0787.0385
M4850.0928.0510
?? Anti-galling note: Apply nickel-based anti-seize to washer bearing faces in high-temperature or immersed service. Never use copper-based compounds on nickel alloys.

Industry Applications

Hastelloy C276 Washers Applications — Industries & End Uses

Hastelloy C276 Washers from RealBolt are specified across chemical processing, pharmaceutical, oil and gas, and FGD where excellent corrosion resistance and 800 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples. Select an industry below to see specific Hastelloy C276 washers application details and RealBolt stock availability.
Hastelloy C276 flat washers and spring washers are the standard specification for flange assemblies on hydrochloric acid reactors, sulfuric acid heat exchangers, and mixed halide process vessels. The alloy resists both oxidising and reducing acid attack that destroys stainless steel washers within weeks of service.
C276 washers are used in ASME B16.5 flange bolt assemblies on sour gas wellheads, H2S scrubbers, and amine treating units. NACE MR0175/ISO 15156 compliant with hardness controlled to 35 HRC max. Specified in Shell DEP and ExxonMobil EMSP for sour service flange hardware.
Flat and fender washers for offshore platform structural connections, splash-zone pipe supports, and subsea valve actuator assemblies where PREN 70+ is required for long-term seawater immersion. Eliminates crevice corrosion under washer bearing faces – the primary failure mode for 316L washers in offshore service.
Hastelloy C276 washers are used in pharmaceutical reactor closures, CIP/SIP system flange connections, and high-purity process piping where resistance to acetic acid, formic acid, and chlorinated cleaning agents is required alongside full compliance with surface finish and traceability requirements.

Hastelloy C276 Washers Standards & International Certifications

Hastelloy C276 Washers from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, PMI (XRF), NACE MR0175/ISO 15156, and NABL-accredited lab reports — available on request for all orders.
Standards
DIN 125A DIN 126 DIN 127 DIN 128 ISO 7089 ISO 7090 ASME B18.21.1 EN ISO 7089 IS 5372 IS 1367
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy Hastelloy C276 Washers from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Hastelloy C276 Washers — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
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Answers for Buyers

Hastelloy C276 Washers — Frequently Asked Questions

Browse expert answers to common questions about Hastelloy C276 Washers from RealBolt — covering acid corrosion resistance, NACE MR0175 compliance, ASTM standards, available sizes, and MTC documentation. Contact our technical team directly for project-specific guidance on Hastelloy C276 washers selection and pricing.
Hastelloy C276 flat washers are available to DIN 125 (normal series), DIN 9021 (large OD series), ISO 7089, and ISO 7093. Inch-series plain washers are supplied per ASME B18.22.1 and lock washers per ASME B18.21.1. Custom dimensions – including non-standard OD, ID, and thickness combinations for ASME B16.5 flange assemblies – are available with a 10-15 working day lead time.
Yes – Hastelloy C276 is one of the few alloys with genuine resistance to hydrochloric acid across a wide concentration and temperature range. At ambient temperature, C276 washers resist HCl concentrations up to 40%. At elevated temperatures, resistance depends on concentration, but C276 consistently outperforms all stainless steel and duplex grades. It is the benchmark alloy for HCl reactor and scrubber flange hardware worldwide.
Yes – with a PREN exceeding 70, Hastelloy C276 washers are completely immune to pitting and crevice corrosion in seawater, including under the washer bearing face where oxygen-depleted crevice conditions develop. They are listed in NORSOK MDS D47 for offshore structural fastener assemblies and are specified by major operators including Shell and ExxonMobil for splash-zone and fully immersed connections without cathodic protection or coating.
Both alloys are nickel-molybdenum-chromium grades, but C22 (UNS N06022) contains higher chromium (20-22.5%) and lower molybdenum (12.5-14.5%) than C276. C22 offers superior resistance to oxidising acids and mixed acid environments, while C276 performs better in pure reducing acid service such as HCl and dilute H2SO4. For most chemical processing and offshore applications, C276 is the more economical and widely stocked choice. We supply both grades and can advise on selection based on your process chemistry.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
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  • Mexico
  • Germany
  • UK
  • France
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  • Netherlands
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  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
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