UNS C54400
Phosphor Bronze
Fasteners
Why Phosphorus Improves Fatigue Life
UNS C54400 is built from a copper-tin base with two further deliberate additions, each solving a distinct problem. Tin bronze alone already provides good strength and corrosion resistance, but phosphorus is added specifically as a deoxidizer during casting and, critically, remains present in small residual amounts that measurably improve the alloy’s fatigue strength and elastic spring-back behavior — the genuine reason “phosphor bronze” as a family has a long, established reputation in springs, electrical contacts, and components subject to repeated flexing.
Lead is the second addition, present specifically for machinability — much like tellurium in copper, lead forms soft, dispersed particles that act as internal chip-breakers, letting this alloy machine cleanly at production volumes despite its underlying copper-tin toughness. Zinc rounds out the composition, contributing to strength and cost efficiency without significantly compromising the alloy’s other properties.
That combination makes UNS C54400 the practical choice specifically where a fastener or precision component needs to survive genuine cyclic loading or vibration — not just static strength — while still being manufacturable efficiently. Good general corrosion resistance, including reasonable performance in marine atmospheres, comes as a genuine additional benefit of the copper-based chemistry, though it’s a secondary consideration to the fatigue and machinability story that defines this alloy.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our UNS C54400 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 Fatigue & Spring Performance
Phosphorus content improves resilience under repeated flexing and cyclic loading.
Genuinely Free-Machining
Lead-enhanced chip-breaking behavior for efficient, cost-effective production machining.
Good General Corrosion Resistance
A genuine, secondary benefit of the copper-based chemistry, including marine atmospheres.
Verified Mechanical Properties
Batch testing confirms genuine alloy content and mechanical properties for every lot.
UNS C54400 vs UNS C64200 — Quick Reference
Confirming whether cyclic/fatigue loading is genuinely the driving requirement versus direct seawater immersion resistance, which points toward our aluminium silicon bronze instead. This table is the quick reference we use with buyers before quoting.
| Aspect | UNS C54400 Phosphor Bronze | UNS C64200 Al-Si Bronze |
|---|---|---|
| Base Chemistry | Copper-tin-zinc-lead | Copper-aluminium-silicon |
| Fatigue & Spring Behavior | Genuinely superior | Moderate |
| Seawater Immersion Resistance | Good, atmospheric/general marine | Genuinely superior, direct immersion |
| Magnetic Behavior | Non-magnetic | Non-magnetic |
UNS C54400 Specification Details
Nominal Composition
- Copper ~87.5 – 90.5% (Balance)
- Tin ~3.5 – 4.5%
- Zinc ~3.5 – 4.5%
- Lead ~3.5 – 4.5%
Typical Mechanical Range
- Condition Cold Worked / As Supplied
- Fatigue Strength Genuinely Superior
- Machinability Rating Excellent, Free-Cutting
- Corrosion Resistance Good, General/Marine
Fastener Types We Manufacture
- Hex Bolts & Studs Standard & Custom Sizes
- Hex Nuts Standard & Heavy Hex
- Set Screws & Precision Parts Custom Machined
- Custom Machined Parts On Request
Application Areas
Wherever cyclic loading, vibration, or repeated flexing genuinely stresses the fastener beyond static load alone.
Electrical Contact & Spring Hardware
and spring-loaded fastening
Vibration-Prone Marine Hardware
sustained vibration or flexing
Precision Machined Instrumentation
machined fastening components
Non-Magnetic Instrument Fastening
resistant instrument hardware
Standard Export Documentation
Prepared as standard practice for every UNS C54400 fastener shipment.
Mill Test Certificate (MTC)
Heat/lot number, chemical composition, and mechanical property verification for every batch.
Chemical Composition Report
Confirms actual copper, tin, zinc, and lead content fall within the specified UNS C54400 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
UNS C64200 Aluminium Silicon Bronze
Our related copper-based alloy, valued for direct seawater immersion resistance and galling resistance.
View UNS C64200 →UNS C14500 Tellurium Copper
Our high-conductivity copper alloy, valued for electrical performance rather than fatigue resistance.
View UNS C14500 →ASTM A194 Grade 8 Nuts
Our standard stainless grade, an alternative where higher static strength is the priority over fatigue behavior.
View Grade 8 Nuts →Stainless Steel Fasteners Manufacturer India
Our broader fastener manufacturing capability across all major carbon, alloy, stainless, and non-ferrous grades.
View SS Manufacturer Guide →Cyclic Loading
or Vibration Exposure?
Tell us your application and loading conditions — we’ll confirm whether phosphor 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