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    Nord-Lock® Washers — Stop Bolts Shaking Loose

    Wedge-locking washer enquiries for pumps, crushers and process equipment across Australia. Steel, 316L stainless, 254 SMO, Alloy C-276 and Alloy 718 requirements — manufacturer, availability and suitability confirmed at quotation.

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    Genuine brand sourcing

    Nord-Lock® specified? Genuine-product sourcing confirmed per quote — no alternative-brand substitution.

    Built for vibration

    Pumps, crushers, screens and conveyors where joints shake loose.

    Five material families

    Steel through to Alloy 718, matched to your bolting.

    Traceable supply

    Batch records with EN 10204 3.1 certified studs and nuts.

    Genuine Nord-Lock Pairs and Matched Bolting

    Genuine Nord-Lock wedge-locking washer pair standing on edge showing radial teeth and inner cam faces
    Genuine pair on edge — radial teeth and cam faces
    Genuine Nord-Lock wedge-locking washer pair with cam faces together and radial teeth outer
    Genuine pair flat, cam face to cam face
    Nuts and washers staged for vibration-critical bolted assemblies
    Nuts and washers staged for matched sets

    Nord-Lock® is a registered trademark of the Nord-Lock Group. EMG is not an authorised distributor and claims no affiliation; genuine-product sourcing is confirmed per enquiry.

    How Wedge-Locking Works

    Each pair has cams on the inner faces and radial teeth on the outer faces. The teeth grip the nut and joint surface, so the only movement possible is between the cams.

    Because the cam angle is steeper than the thread pitch, any loosening rotation forces the cams to ride up — increasing bolt tension instead of releasing it. Lubrication does not defeat it, because the lock is geometric, not friction-based.

    Diagram: cam angle greater than thread pitch angle in a wedge-locking washer pairNut / bolt headJoint surfaceCams αTeethCam angle α > thread pitch angle β → loosening increases tension

    Choose Your Material

    Steel (Delta Protekt®)

    Mining plant, crushers, heavy vehicles, structural

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    316L Stainless

    Food, water, general process and marine atmospheres

    Request a quote

    254 SMO®

    Seawater, chloride-rich dewatering and offshore

    View grade page

    Alloy C-276

    Acid leach, chlorine and severe chemical service

    View grade page

    Alloy 718

    High temperature, turbines, HPHT and subsea

    View grade page

    Manufacturer material references; availability by size confirmed at quotation.

    Wedge-Locking vs Conventional Locking

    MethodLocking principleUnder severe vibrationLubricated threads
    Wedge-locking pairTension-based — cam geometryHolds clamp loadUnaffected
    Split / spring washerFriction and spring forceLoosensReduced
    Serrated / tooth washerSurface biteLoosensReduced
    Nylon insert nutThread frictionPrevents loss, not preloadTemperature-limited

    General comparison; joint design and the manufacturer's instructions govern selection.

    Mining processing plant where vibration-critical bolted joints are common
    Crushers, screens and pumps — where joints shake loose
    Two sizes of genuine Nord-Lock wedge-locking washer pairs supplied for vibration-critical bolted joints
    Genuine Nord-Lock washer pairs in two sizes — size and material confirmed per RFQ
    EN 10204 3.1 Certified
    ISO 9001 Quality
    Heavy hex nuts staged for assembly with locking washer sets
    Locking washers supplied as complete bolt, nut and washer sets

    Overview

    Wedge-locking washers work in pairs with cams on the inner faces and serrations against the nut or bolt head and joint surface. Cam geometry resists rotational loosening by increasing bolt tension when the cams climb. Correct installation, compatible surface hardness and joint geometry remain essential; washers do not replace the joint designer's preload procedure. EMG accepts material-specific washer RFQs alongside matched studs, nuts and bolts. EMG accepts genuine Nord-Lock enquiries only, with no alternative-brand substitution. Manufacturer, washer batch records and bolting certificates are confirmed separately before order.

    EMG accepts Australia-wide wedge-locking washer RFQs by material, bolt size, brand requirement and quantity; manufacturer, documentation and lead time are confirmed before supply.

    Typical Applications

    • Rotating equipment: pump baseplates, compressor mounts, fan and blower housings
    • Mining and quarry plant: crushers, screens, conveyor structures and liner bolting
    • Rail, transit and heavy vehicle assemblies subject to continuous dynamic load
    • Wind, hydro and turbine auxiliaries where joint relaxation drives unplanned outages
    • Structural and secondary steel connections where re-torquing access is limited
    • Skid, package and modular equipment shipped and commissioned under vibration

    Wedge-Locking Washer Types We Supply

    • Standard washer pairs — material-specific size range confirmed at quotation
    • SP type with enlarged outer diameter for soft, painted or oversized-hole surfaces
    • Conical washer enquiries for vibration and relaxation — variant availability confirmed
    • Large-diameter wedge-locking washer pairs for heavy structural and flange bolting
    • Matched sets supplied with ASTM A193 studs, hex bolts and A194 nuts
    • Coated bolt and washer combinations where cathodic or barrier protection is specified

    Common Materials & Grades

    Steel — EN 1.7182 (manufacturer reference)316L stainless — EN 1.4404 (manufacturer reference)254 SMO — EN 1.4547 (manufacturer reference)Alloy C-276 — EN 2.4819 or equivalent (manufacturer reference)Alloy 718 — EN 2.4668 or equivalent (manufacturer reference)Offered washer grade, coating, manufacturer and availability confirmed per RFQ

    Standards & Documentation

    • EN 10204 3.1 material certification on the bolting supplied with each washer set
    • Hardness and dimensional inspection records available on request
    • Washer manufacturer batch records confirmed separately from stud and nut material certificates
    • ISO 9001:2015 certified quality management system
    • Bolt tightening to the joint designer's torque specification — washer pairs do not change the required bolt preload method
    • Supplied with 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

    254 SMO Wedge-Locking WashersAlloy C-276 Wedge-Locking WashersAlloy 718 Wedge-Locking WashersNuts & WashersStud BoltsHex BoltsCoated FastenersASTM StandardsBolt Torque CalculatorMining & Minerals

    Five manufacturer material families, selected around the joint

    Nord-Lock Original lists steel, stainless steel, 254 SMO, Alloy C-276 and Alloy 718. Duplex and super duplex are not listed in that five-material range: duplex bolting does not imply a duplex wedge-locking washer. For chloride-exposed pump assemblies, acidic mineral-processing circuits or demanding power equipment, submit actual service conditions and the required material specification. We confirm the manufacturer, material, size and documentation rather than treating all washer types as interchangeable.

    Standard, SP and conical washer enquiries

    Standard pairs, enlarged-outer-diameter SP washers and conical variants address different joint requirements. Surface hardness, bearing area, hole geometry and relaxation all need review against manufacturer guidance. Availability is material- and size-specific; a conical or SP version cannot be assumed available in every alloy. Include the proprietary part number where your maintenance specification names one.

    Mining shutdown and pump maintenance packages

    Send your equipment or joint list with bolt size, washer pairs required, bolt and nut grade, coating, site postcode and required date. EMG can review matched bolting and washer requirements under one enquiry for crushers, screens, pump baseplates and compressor mounts. Washer certification and batch traceability are agreed separately from EN 10204 certificates for the studs and nuts. Lead times are confirmed against the actual sourcing route; no stock or urgent delivery is implied.

    FREQUENTLY ASKED QUESTIONS

    Technical FAQs

    How do wedge-locking washers stop bolts from vibrating loose?

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    They work in pairs with cams facing each other. The cam angle is greater than the thread pitch, so if the bolt or nut tries to rotate loose the cams must climb over each other, which increases tension in the joint rather than releasing it. Radial teeth on the outer faces grip the bolt head and the joint surface so the pair can only move against itself.

    Are wedge-locking washers affected by lubrication?

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    No. Because the locking action is mechanical — tension created by cam geometry — it does not rely on friction between surfaces. This is the key difference from spring, serrated and toothed locking washers, whose effectiveness drops sharply on lubricated, coated or hardened surfaces.

    What is the difference between standard, SP and X-series wedge-locking washers?

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    Standard washers suit hardened and machined steel surfaces. SP washers share the same cam geometry with a larger outer diameter for soft, painted or oversized-hole applications where bearing pressure must be spread. X-series washers add a conical shape that maintains preload where the joint is exposed to both vibration and relaxation, such as painted surfaces, castings and short clamp lengths.

    Can wedge-locking washers be reused?

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    They can be reused where the cams and radial teeth show no visible wear or damage, and they must always be reinstalled in pairs, cam face to cam face. For safety-critical bolting in oil and gas, LNG and mining applications, most maintenance specifications treat locking washers as consumables and replace them at each disassembly.

    Do wedge-locking washers change the tightening torque?

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    No. The joint is still tightened to the torque or preload specified by the joint designer for that bolt grade, size and lubrication condition. Removal behaviour depends on the joint; untightening torque alone is not proof of correct installation. Follow the actual washer manufacturer’s instructions.

    Which materials are available for corrosive and offshore service?

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    The published Nord-Lock Original families are steel, stainless steel, 254 SMO, Alloy C-276 and Alloy 718. Submit process exposure and the required brand so EMG can confirm material-specific availability and documentation. These are manufacturer references, not an EMG stock commitment. Duplex bolting does not mean the washer is duplex.

    Do you supply Nord-Lock washers in Australia?

    +
    EMG accepts genuine Nord-Lock washer enquiries across Australia, with no alternative-brand substitution. Genuine-product sourcing, size, material, batch records and lead time must be confirmed before order. EMG does not claim authorised-distributor status. Nord-Lock® is a registered trademark of the Nord-Lock Group.
    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. EMG accepts genuine Nord-Lock enquiries only; no alternative brand is substituted.

    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.

    Request a washer quote

    GET IN TOUCH

    Need a Quote for Nord-Lock® Washers?

    Send us the size, grade and quantity — or your drawings and bill of materials — and we'll return a technical quote for nord-lock® washers with lead times and certification included.

    Request a Nord-Lock® Washers QuoteCall Now

    Phone

    +61 (0)7 4055 6928

    Email

    sales@energymaterialsgroup.com

    Emergency Support

    24/7 availability for critical projects