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    Alloy C-276 Wedge-Locking Washers for Aggressive Chemical Service

    Wedge-locking washer enquiries in Alloy C-276 (EN 2.4819 / UNS N10276) for acidic process plant, flue gas systems and chemical leaching circuits. Manufacturer, size availability and batch documentation confirmed per quotation.

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    Industrial washers and heavy hex nuts staged for a chemical-resistant bolted assembly
    Washer pairs matched to bolt grade and joint conditions
    EN 10204 3.1 Certified
    ISO 9001 Quality
    Heavy hex nuts prepared for assembly with nickel alloy locking washers
    Washers quoted alongside matched nickel alloy bolting

    Overview

    Alloy C-276 (EN 2.4819, UNS N10276, commonly referenced as Hastelloy C-276) is a nickel-molybdenum-chromium alloy with tungsten, resistant to a wide range of oxidising and reducing media — including wet chlorine, hypochlorites, sulphuric and hydrochloric acid environments and chloride-contaminated process streams. It is one of the five material families in the Nord-Lock Original range. Where process chemistry destroys stainless washers, C-276 is the manufacturer's usual nickel-alloy answer. EMG accepts material-specific RFQs and confirms the offered manufacturer, size availability, documentation and lead time before order; these are manufacturer reference grades, not an EMG stock commitment.

    For acid and chloride process service, EMG quotes Alloy C-276 wedge-locking washers with manufacturer, size availability and documentation confirmed before supply.

    Typical Applications

    • Flue gas desulfurisation (FGD) scrubbers, ducting and fan assemblies
    • Sulphuric, hydrochloric and mixed-acid process equipment
    • Chemical leaching circuits, including pressure acid leach laterite processing
    • Chlor-alkali, hypochlorite and wet chlorine handling plant
    • Sour gas and refinery equipment where chlorides and vibration combine
    • Agitators, reactors and tank-mounted equipment subject to continuous vibration

    Alloy C-276 Washer Configurations

    • Standard washer pairs in Alloy C-276 — size range confirmed at quotation
    • SP type with enlarged outer diameter, where available in this grade
    • Matched sets with C-276 or compatible nickel alloy studs, bolts and nuts
    • Complete flange and equipment bolting packages for corrosive service
    • Replacement washer pairs for maintenance specifications naming a proprietary part number

    Common Materials & Grades

    Alloy C-276 — EN 2.4819 / UNS N10276 (manufacturer reference)Nickel-molybdenum-chromium with tungsten for broad acid resistanceOffered grade, manufacturer and size availability confirmed per RFQ254 SMO, 316L and Alloy 718 alternatives reviewed where C-276 is unavailableNo substitution away from a named brand without buyer and engineering approval

    Standards & Documentation

    • EN 10204 3.1 material certification on the bolting supplied with each washer set
    • Washer manufacturer batch records confirmed separately from stud and nut certificates
    • PMI verification available on request for alloy confirmation
    • ISO 9001:2015 certified quality management system
    • Bolt tightening to the joint designer's specification — washers do not change the required preload method
    • Heat-number traceable studs and nuts where full assembly traceability is required

    NEED MACHINED COMPONENTS TOO?

    Spacers, blinds, special nuts, shafts and bushes — supplied to your drawing with the same traceability as your bolting. Precision Machined Components →

    RELATED RESOURCES

    Wedge-Locking Washers (all materials)254 SMO Wedge-Locking WashersAlloy 718 Wedge-Locking WashersNuts & WashersNickel Alloy MaterialsProcess Plant FastenersMining & Minerals

    Where C-276 earns its place in a bolted joint

    Stainless washers fail quietly in acidic and chloride process service: the serrations and cam faces that create the locking action are also crevices, and crevice attack there destroys function long before the stud shows damage. C-276 tolerates both oxidising and reducing chemistries that defeat 316L and 254 SMO, including wet chlorine and contaminated acids. It is not the cheapest washer material and should be specified where the exposure justifies it — send the process stream, concentration and aeration conditions and we confirm whether the C-276 washer family fits.

    Leaching plants and Australian minerals processing

    Pressure acid leach and heap leach operations across Australian laterite and base-metal projects combine sulphuric acid, chlorides, slurry abrasion and heavy vibration on agitators, autoclave auxiliaries and pump assemblies. Washer selection in these circuits should be reviewed against the actual duty, not a generic corrosion table. EMG accepts RFQs from processing plants Australia-wide and confirms material, sourcing and documentation per application.

    Sourcing reality for nickel alloy washers

    C-276 washer availability is size- and variant-specific, and lead times differ substantially from steel washers. Genuine-brand sourcing must be confirmed before we quote, and where a maintenance specification names a proprietary part number, include it in the RFQ. Where genuine supply cannot be confirmed in your timeframe, we review alternatives only with your engineering approval — never by default substitution.

    FREQUENTLY ASKED QUESTIONS

    Technical FAQs

    When should I specify C-276 instead of 254 SMO washers?

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    254 SMO covers chloride pitting and crevice service such as seawater. C-276 adds resistance to oxidising and reducing acids, wet chlorine and mixed chemistries found in FGD, leaching and chlor-alkali plant. If the exposure is acidic beyond chloride-only service, C-276 is usually the appropriate family — confirm the actual chemistry with your materials engineer.

    Are C-276 wedge-locking washers available in all sizes?

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    No. Nickel alloy washer availability is narrower than steel or stainless and varies by size and variant. Send the bolt size, thread and washer type required and we confirm availability, sourcing route and lead time before quoting.

    What bolting should C-276 washers be paired with?

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    Typically C-276 or compatible nickel alloy studs and nuts so the assembly's corrosion resistance is consistent. Pairing an exotic washer with uncoated carbon-steel bolting leaves the weakest component exposed. EMG can quote the complete assembly under one enquiry.

    Do you supply genuine Nord-Lock C-276 washers in Australia?

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    EMG accepts Australia-wide washer RFQs. Tell us whether genuine Nord-Lock is mandatory or an alternative may be proposed. Genuine-product sourcing must be confirmed; EMG does not claim authorised-distributor status or certified equivalence. Nord-Lock® is a registered trademark of the Nord-Lock Group. No substitution is made without buyer and engineering approval.

    What documentation is supplied with C-276 washers?

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    Washer manufacturer batch records are agreed at quotation, separate from the EN 10204 3.1 certificates for the studs and nuts. PMI verification of the washer alloy can be arranged on request. State documentation requirements in the RFQ so they are confirmed before order.
    MATERIAL-SPECIFIC WASHER ENQUIRIES

    Specify the washer, not just the bolt

    Nord-Lock's Original range lists five material families. These are manufacturer references, not a claim of EMG stock, authorised distribution or certified interchangeability. We confirm the offered manufacturer, material, dimensions, documentation and lead time in your quotation. A named brand is not substituted without your approval.

    Steel

    EN 1.7182

    General steel joints; confirm coating and mating-surface hardness.

    316L stainless steel

    EN 1.4404

    General stainless assemblies; chloride and acid exposure need separate review.

    254 SMO

    EN 1.4547

    Chloride-exposed pumps, seawater and desalination duties, subject to service review.

    Alloy C-276

    EN 2.4819 or equivalent

    Acidic process and chemical plant applications, subject to service review.

    Alloy 718

    EN 2.4668 or equivalent

    Turbine, power and demanding process equipment, subject to joint approval.

    Reference: Nord-Lock Original wedge-locking technology. Material, size and SP / conical availability must be checked together; not every variant is offered in every grade.

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    Send us the size, grade and quantity — or your drawings and bill of materials — and we'll return a technical quote for alloy c-276 wedge-locking washers with lead times and certification included.

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