UNS C64200
Aluminium Silicon Bronze
Fasteners
Why Aluminium Silicon Bronze
UNS C64200 is a copper-based alloy, not a steel — roughly 91% copper alloyed with aluminium and silicon, plus a small cobalt addition in most commercial variants. That copper base is precisely what makes it valuable in situations where steel, even high-grade stainless steel, isn’t the right answer.
Its seawater corrosion resistance is genuinely excellent — aluminium bronzes as a family are among the most respected copper alloys for direct, sustained saltwater exposure, forming a stable, adherent aluminium oxide film that resists the pitting and crevice corrosion mechanisms that even 316 stainless steel can suffer in stagnant or chloride-concentrated seawater conditions.
Its non-magnetic behavior is a genuine, absolute property — as a copper alloy, C64200 has none of stainless steel’s partial or condition-dependent magnetic response, making it the correct default wherever magnetic signature must be minimized, such as certain naval, subsea instrumentation, or MRI-adjacent equipment applications.
Its resistance to galling and seizure when mated against stainless steel fasteners is also genuine and well-documented — stainless-to-stainless threaded connections are notoriously prone to galling under torque, and aluminium silicon bronze nuts or bolts mated against stainless counterparts largely avoid this failure mode, a real practical advantage in valve, pump, and marine hardware assembly.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our UNS C64200 fastener range is manufactured and verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Material Genuinely Applies
Genuine Seawater Corrosion Resistance
A stable aluminium oxide film resists pitting and crevice attack in direct saltwater exposure.
Genuine Non-Magnetic Behavior
An absolute, unconditional property, unlike stainless steel’s partial magnetic response.
Genuine Galling & Seizure Resistance
Avoids the thread-galling failure mode common to stainless-to-stainless mated connections.
Verified Mechanical Properties
Batch testing confirms genuine alloy content and mechanical properties for every lot.
UNS C64200 vs 316 Stainless — Quick Reference
Confirming whether non-magnetic behavior or galling resistance is genuinely the driving requirement before choosing bronze over stainless. This table is the quick reference we use with buyers before quoting.
| Aspect | UNS C64200 Bronze | 316 Stainless Steel |
|---|---|---|
| Base Metal | Copper alloy | Iron-based alloy |
| Magnetic Behavior | Fully non-magnetic | Weakly magnetic, condition-dependent |
| Galling Against Stainless | Genuinely resistant | Prone to galling, stainless-on-stainless |
| Relative Strength | Moderate | Generally higher |
UNS C64200 Specification Details
Nominal Composition
- Copper ~91% (Balance)
- Aluminium ~6.5 – 7.5%
- Silicon ~1.5 – 2.5%
- Cobalt Small Addition, Common Variants
Typical Mechanical Range
- Condition Cold Worked / As Supplied
- Magnetic Permeability Effectively None
- Corrosion Resistance Excellent, Seawater
- Galling Resistance Genuinely Superior
Fastener Types We Manufacture
- Hex Bolts & Studs Standard & Custom Sizes
- Hex Nuts Standard & Heavy Hex
- Washers Matching Material
- Custom Machined Parts On Request
Application Areas
Wherever seawater exposure, non-magnetic requirements, or galling resistance against stainless steel are genuinely present.
Marine & Offshore Hardware
hull and deck fittings
Valve & Pump Assembly
against stainless components
Naval & Subsea Instrumentation
requirements
Desalination & Coastal Process Equipment
process water exposure
Standard Export Documentation
Prepared as standard practice for every UNS C64200 fastener shipment.
Mill Test Certificate (MTC)
Heat/lot number, chemical composition, and mechanical property verification for every batch.
Chemical Composition Report
Confirms actual copper, aluminium, and silicon content fall within the specified UNS C64200 range.
Certificate of Conformance
Confirms the shipment matches the purchase order specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical and dimensional testing available on request.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
ASTM A194 Grade 8M Nuts
Our chloride-resistant 316 stainless grade, the common alternative where magnetic behavior isn’t a concern.
View Grade 8M Nuts →ASTM A194 Grade 8MLN Nuts
Our combined chloride and weld-decay resistant stainless grade, for weld-critical marine assemblies.
View Grade 8MLN Nuts →Hastelloy B3 Stud Bolts (UNS N10675)
Our nickel-molybdenum alloy for extreme reducing-acid environments beyond bronze’s capability.
View Hastelloy B3 Studs →Stainless Steel Fasteners Manufacturer India
Our broader fastener manufacturing capability across all major carbon, alloy, stainless, and non-ferrous grades.
View SS Manufacturer Guide →Marine, Non-Magnetic,
or Galling-Sensitive Service?
Tell us your application and mating material — we’ll confirm whether aluminium silicon bronze genuinely fits, and quote with full documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in