Silicon Bronze Flanged Nuts

Silicon Bronze Flanged Nuts

Electrical Accessories India manufactures silicon bronze flanged nuts in serrated and non-serrated bearing flange configurations for marine, offshore, coastal substation, and chemical plant electrical assembly applications. Flanged nuts combine the functions of a hex nut and a bearing washer into one component, providing a larger clamping surface area, self-locking capability (serrated flange), and reduced pull-through tendency in sheet metal and thin panel assemblies. In silicon bronze, these fasteners add the critical material advantage of superior seawater and chemical corrosion resistance, non-sparking property, and long-service-life without dezincification—essential characteristics for electrical fasteners in aggressive service environments.

Product Overview

Design and Function of Silicon Bronze Flanged Nuts

A flanged nut integrates a hex nut head with a wider circular bearing flange at the base. The serrated-flange version (DIN 6923 with serrations) provides a prevailing-torque self-locking action through the serration teeth biting into the mating surface, eliminating the need for a separate lock washer. The non-serrated flanged nut (smooth flange) provides a large bearing area without the surface-marking effect of serrations—preferred for softer materials (aluminium panels, copper busbars, composite enclosure skins) where surface integrity is important. The flange also bridges oversize or irregular holes in electrical panels, improving clamp load distribution.

Silicon Bronze Grade Selection for Flanged Nuts

C65500 (High Silicon Bronze A, 3% Si, ~560 MPa UTS) is the recommended grade for flanged nuts in submerged, buried, and highly corrosive environments (chemical plants, offshore splash zones, buried earthing, coastal soil). C65100 (Low Silicon Bronze B, 1.5% Si, ~450 MPa UTS) is suitable for above-waterline marine, coastal substation hardware, and mildly corrosive industrial environments. Both grades are non-magnetic and non-sparking, qualifying for use in ATEX Zone 1/2 electrical installations. The serration hardness of C65500 flanged nuts is adequate to indent into copper, aluminium, and steel panel surfaces for effective self-locking.

Dimensional Standards – DIN 6923 and ISO 4161

Silicon bronze flanged nuts are dimensioned per DIN 6923 (metric hexagon nuts with flange – serrated) and ISO 4161 (hexagon nuts with flange – non-serrated). The hex head AF dimensions, nut height, flange diameter, and flange thickness conform to the standard for direct interchangeability with carbon steel DIN 6923 nuts. Thread tolerance 6H per ISO 965. Available in metric M4 to M24. Inch-series flanged nuts (UNC 1/4″–3/4″) also available to ASME B18.16.1 profile.

Applications in Electrical Panel and Earthing Systems

Silicon bronze flanged nuts are used in: sheet metal panel assembly for earthing bus bars and conductor supports, cable tray support bracket fasteners in offshore topsides, cable gland panel clamping (where oversize knock-outs require large-bearing flange), equipment earthing strap terminal connections, bonding jumper end terminations, marine engine room electrical panel fasteners, hazardous area junction box cover fasteners, and substation earthing busbar connection hardware. The one-piece nut-and-washer design reduces component count, speeds assembly, and eliminates the risk of loose washer loss during installation in confined spaces.

Self-Locking Performance of Serrated Flange

The serrations on DIN 6923 silicon bronze flanged nuts are machined at 30° to the face, creating 12–24 circumferential teeth that embed into the mating surface on tightening. This provides an initial prevailing torque of 0.5–1.5 Nm (M6–M12) resistant to loosening under vibration per DIN 65151 vibration test. The locking mechanism is effective for 5–10 re-uses, after which the serrations become too worn for reliable locking. For critical vibration-resistant applications, nylon-insert (DIN 985 profile) silicon bronze locknuts are recommended for applications exceeding 10 re-use cycles.

Non-Sparking and ATEX Applications

Silicon bronze flanged nuts are certified as non-sparking per IEC 60079-0 material requirements for use in Group IIA, IIB, and IIC explosive atmosphere equipment enclosures (ATEX Zone 1/2). The flanged configuration is particularly useful in ATEX junction boxes and conduit fittings where a single flanged nut can seal a cable entry when used with an appropriate O-ring or gasket, replacing a separate lock washer + nut combination that could inadvertently lose the washer during installation in a hazardous area.

Compatibility with Silicon Bronze Fastener System

Silicon bronze flanged nuts are designed for use with silicon bronze bolts, silicon bronze hex flanged bolts, and silicon bronze studs from the Electrical Accessories India range. Using matched silicon bronze fasteners throughout an earthing system or marine electrical assembly eliminates all inter-metallic galvanic couples in the fastener assembly, providing maximum corrosion resistance and system reliability in aggressive environments.

Pricing

Silicon bronze flanged nuts are priced at USD 14.90 per kilogram (EXW Jamnagar, India). MOQ 10 kg per size. Kit pricing (bolt + flanged nut + washer) available on request.

Key Features

• Silicon bronze C65500 and C65100 – superior corrosion resistance vs brass
• Serrated flange (DIN 6923) and non-serrated (ISO 4161) configurations
• One-piece nut + washer design – reduces component count, speeds assembly
• Self-locking – no separate lock washer needed (serrated type)
• ATEX non-sparking, non-magnetic
• M4–M24 metric, 1/4″–3/4″ inch series available
• Compatible with full silicon bronze fastener system from same manufacturer

Large Bearing Area for Thin Panel Applications

The flange bearing area of a DIN 6923 M10 flanged nut is approximately 3.5× the bearing area of a standard DIN 934 hex nut alone (without washer). This larger contact area distributes clamp load over a greater panel area, reducing contact stress and preventing pull-through in 1.5–2 mm aluminium panel sheets commonly used in electrical distribution enclosures and cable junction boxes. For pull-through critical applications (lightweight composite enclosures, FRP panels), silicon bronze flanged nuts provide superior resistance to nut-face pull-through vs standard hex nuts.

Marine Panel and Junction Box Assembly

In marine electrical installations (IEC 60092 and ABYC E-11 compliant), all external and bilge-space fasteners must resist seawater. Silicon bronze flanged nuts for marine distribution boards, navigation equipment mounting panels, windlass control panels, engine room junction boxes, and shore power connectors provide: corrosion-free service life of the vessel (20–30+ years), no staining of GRP or aluminium panels from ferrous corrosion products, and compliance with Lloyd’s Register and Bureau Veritas material approval requirements for marine electrical hardware.

Technical Specifications

Product Variants

Applications in Industry

Manufacturing Process

Silicon bronze flanged nuts are produced by cold forging or hot forging (depending on size), followed by CNC tapping and flange serration milling. The flange profile is formed in the forging die, creating the integrated hex-and-flange geometry in a single press stroke. Serrations are formed either during forging (die serration) or by secondary milling/rolling. Thread tapping uses flood-cooled spiral-flute taps optimised for silicon bronze. Each nut is gauged with GO/NO-GO thread plug gauges, and flange diameter/thickness verified with digital callipers. Dimensional sampling per ISO 3269 at AQL 1.0.

Quality Standards and Certifications

Why Choose Electrical Accessories India

• Silicon bronze specialist – flanged nuts, hex nuts, bolts, studs from single source
• Both serrated and non-serrated flange configurations stocked
• USD 14.90/kg competitive pricing
• ATEX and earthing system documentation available
• ISO 9001:2015 certified with EN 10204 3.1 MTR
• Export to marine, offshore, and industrial markets globally

Frequently Asked Questions (FAQ)

1. What is the advantage of a flanged nut over a plain nut with washer?

Flanged nuts combine the nut and washer in one piece: faster assembly, no dropped washer risk (critical in offshore/marine confined spaces), consistent clamp area every time, and with serrated flange, built-in locking without separate component. For production-line panel assembly, flanged nuts reduce parts count and assembly time significantly.

2. Can silicon bronze flanged nuts be reused?

Non-serrated flanged nuts can be reused indefinitely within their load limits. Serrated flanged nuts provide effective locking for 5–10 re-uses; after which serrations are sufficiently worn that a fresh nut should be used for critical torque-retention applications.

3. Are silicon bronze flanged nuts compatible with stainless steel bolts?

Silicon bronze is galvanically compatible with stainless steel in most atmospheres (small potential difference). However, for seawater-immersed applications, use silicon bronze bolts with silicon bronze flanged nuts throughout to eliminate all galvanic couples in the fastener assembly.

4. What flange diameter is available for M10 silicon bronze flanged nut?

DIN 6923 M10 silicon bronze flanged nut: hex AF = 15 mm, flange OD = 19 mm, total height = 10.8 mm, thread pitch = 1.5 mm, property class 04. Contact us for exact dimensional drawings for your design.

5. Do you stock silicon bronze flanged nuts or are they made to order?

M6, M8, M10, M12, M16 DIN 6923 silicon bronze flanged nuts (C65500) are stocked for short-notice delivery. Other sizes (M4, M20, M24) are manufactured to order with 3–4 week lead time. Contact us with your complete BOM for stock availability confirmation.

6. What is the price of silicon bronze flanged nuts?

USD 14.90 per kilogram (EXW Jamnagar, India). Volume discount applies from 100 kg. Contact for formal quotation.

Equivalent Terms and Multilingual Reference

Related Products and Linked Terms

• Silicon Bronze Hex Nuts
• Silicon Bronze Bolts
• Silicon Bronze Hex Flanged Bolts
• Silicon Bronze Studs
• Brass Panel Nuts
• Silicon bronze washers, non-sparking flanged nuts, marine grade fasteners, DIN 6923 bronze nuts, ATEX fasteners

Request a Quote

Electrical Accessories India supplies silicon bronze flanged nuts for marine, offshore, coastal, and chemical plant applications. Pricing: USD 14.90 per kilogram (EXW Jamnagar, India). Contact our engineering sales team for project supply.

Email: info@elecaccs.com | Location: Jamnagar, Gujarat, India

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