C51100 Phosphor Bronze

C51100 Phosphor Bronze

89–91%
Copper Content
O/H02/H04
Temper
Excellent
Formability
C51100 phosphor bronze is a copper-tin alloy offering an excellent balance of strength, formability, fatigue resistance, and electrical conductivity. It is widely used in springs, connectors, electrical contacts, diaphragms, and precision electronic components.
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Lead Time: 3-5 Business Days

Product Overview

C51100 phosphor bronze is a medium-tin copper alloy containing approximately 4% tin with controlled phosphorus additions to improve wear resistance, fatigue strength, and mechanical performance. It provides a balance between the conductivity of pure copper and the strength of higher-tin phosphor bronze alloys.

Produced through precision rolling, drawing, and heat treatment processes, C51100 bronze offers excellent elasticity, dimensional stability, and corrosion resistance. Compared with C51000, it provides similar conductivity while maintaining excellent spring properties and forming characteristics.

C51100 phosphor bronze is extensively used in electrical connectors, spring contacts, relay components, precision stampings, and industrial wear parts where durability and fatigue resistance are critical. It is widely applied across electronics, telecommunications, automotive, aerospace, and industrial manufacturing industries.

Key Features

Excellent fatigue resistance
Outstanding spring performance
Good wear resistance
High corrosion resistance
Reliable electrical conductivity
Excellent formability and stampability

Available Sizes

Copper Shape Thickness (mm) Width/Diameter (mm) Length (m)
Bar - Φ5-200 1-6
Wire - Φ0.05-10 Customize
Sheet 0.25-6 500-2500 1-6
Plate 6-200 200-3000 1-6
Strip 0.15-6 8-610 Customize
Tube OD: φ2-600; WT:φ0.2-100mm - 1-6
Coil 0.15-6 3-1250 1-6
Foil < 0.15 10-1350 Customize
Profile Customized Customize Customize

* Custom sizes available upon request. Contact our sales team for special requirements.

Technical Specifications

Precision data for engineering decisions. All values tested per ASTM standards.

01 Material Properties

Specification Value Notes
Cu Content 93.5–96.0% Phosphor bronze composition
Sn Content 3.5–4.5% Provides strength and wear resistance
P Content 0.03–0.35% Improves fatigue performance
Density 8.84 g/cm³ Typical value
Electrical Conductivity ~16-18% IACS Typical annealed condition
Tensile Strength 400-700 MPa Depends on temper
Elongation ≥ 12% Varies by temper
Hardness 75-190 HV Depends on temper
Available Tempers O / H02 / H04 / Spring Temper Custom temper optional
Elongation ≥ 35% Typical annealed/extruded condition
Fabrication Stamping / Forming / Drawing Excellent cold workability
ASTM Standard ASTM B103 / ASTM B139 EN & JIS available

Applications & Use Cases

Proven solutions across diverse industries. From aerospace to marine environments.

Frequently Asked Questions — C51100 Phosphor Bronze

Practical FAQ for engineers and buyers specifying C51100 phosphor bronze (CuSn4).

C51100 is the lowest-tin commercial phosphor bronze, a copper-tin-phosphorus alloy with about 3.5–4.9% tin and phosphorus 0.03–0.35% (deoxidizer/strengthener). It is covered by ASTM B103/B103M (plate, sheet, strip, rolled bar) and ASTM B139 (rod, bar). It is a wrought spring-grade alloy.
With roughly 4% tin versus 5% in C51000, C51100 is the softest and most formable of the common phosphor bronzes, with slightly lower strength. It is the easier grade to deep-draw and stamp where high spring load is not required, and it costs marginally less.
In the annealed (O) condition tensile strength is about 300–400 MPa with elongation 40–55%. Strength rises with cold work; half-hard and harder tempers reach 450–600+ MPa for light spring and formed parts. Electrical conductivity is roughly 18–24% IACS and the alloy is non-magnetic.
Used for electrical terminals and connectors, light-load springs, relay parts, switch contacts, and intricate stamped or drawn components where formability and moderate strength matter more than maximum spring performance.
Yes. We supply C51100 strip, sheet, and bar to ASTM B103/B139 with MTR/MTC per order and SGS on request. Custom tempers (O, 1/4H, 1/2H, H) and sizes are available at low MOQ with 10–60 day lead times, plus cutting and finishing. Quote requests get a response within 1 business hour.
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