28
Cu
Copper
Kalan
CuSn5P
CuSn5P | Phosphor Bronze | EN CuSn5 / CW451K
KUPTİN® P5 (CuSn5 / CW451K) is a phosphor tin bronze combining high elasticity, fatigue strength, cold formability and corrosion resistance.
- Alloy
- CuSn5
- EN
- CuSn5 / CW451K
- Close UNS grade
- C51000 (not identical)
- Former BS
- PB102 (historical close grade)
- Historical designation
- CuSn5P (AFNOR)
- Density
- 8.85 g/cm³
01. Chemical Composition (%)
50
Sn
Tin
%4,50–5,50
15
P
Phosphorus
%0,01–0,40
26
Fe
Iron
%0,10 Max
28
Ni
Nickel
%0,20 Max
82
Pb
Lead
%0,02 Max
30
Zn
Zinc
%0,20 Max
02. Mechanical Properties
| Property | Unit | Value | Test Method |
|---|---|---|---|
| Tensile Strength Rm | MPa | R310 310-390; R400 400-500; R490 490-580; R550 550-640; R630 630-720; R690 ≥690 | EN 1652; dependent on flat product and condition |
| 0.2% Proof Strength Rp0.2 | MPa | R310 ≤250*; R400 ≥240; R490 ≥430; R550 ≥510; R630 ≥600; R690 ≥670 | EN 1652; *informative value |
| Elongation | % | A50 (≤2.5 mm): R310 ≥45; R400 ≥14; R490 ≥8; R550 ≥4; R630 ≥2. A (>2.5 mm): R310 ≥55; R400 ≥17; R490 ≥10 | EN 1652; dependent on thickness and condition |
| Hardness | HV | H075 75-105; H120 120-160; H160 160-190; H180 180-210; H200 200-230; H220 ≥220 | EN 1652; H conditions are alternatives to R conditions |
| Density | g/cm³ | approximately 8.85 | Typical value |
03. Applications
- Contact springs
- Electrical and signal connectors
- Terminals and contact blades
- Relay and switch components
- Clips, washers and cotter pins
- Cold-formed screws, rivets and fasteners
- Precision stamped and bent parts
- Membranes, diaphragms and bellows
- Bourdon tubes and instrument springs
- Thin-section sliding and wear elements
04. Manufacturing Technology and Supply Forms
Manufacturing TechnologyPrincipal forms are cold-rolled strip and sheet, drawn wire, rod, profile and seamless tube. Mechanical properties must be specified with product form, thickness and either R or H condition. Special cast products must not be represented as CW451K or EN 1652 compliant; they require a separate customer specification and actual chemical and mechanical test results.
Supply FormsCustom Casting, Hollow Bar / Pipe, Flat Bar / Plate, Round Bar
05. Standards and Comparable Grades
06. Technical Description
View Detailed Technical Description
What Is CuSn5P?
CuSn5P is a wrought phosphor bronze containing approximately 5% tin and controlled phosphorus. Its correct EN alloy designation is CuSn5 and its material number is CW451K. CuSn5P appears in commercial use and historical French/AFNOR sources. Tin contributes strength and corrosion resistance, while phosphorus supports deoxidation and wear behaviour.
Chemical Composition
For CuSn5 / CW451K, Sn is 4.50-5.50% and P is 0.01-0.40%. Maximum limits are Fe 0.10%, Ni 0.20%, Pb 0.02%, Zn 0.20% and other elements 0.20% total; copper is the remainder. Detailed limits are listed in the Chemical Composition table.
Mechanical Properties
The mechanical properties of CuSn5 vary significantly with product form, thickness and degree of cold work. EN 1652 flat-product references cover strength conditions from R310 to R690, with tensile strength rising from the 310 MPa level to 690 MPa and above. As strength increases, elongation and formability decrease. A single tensile, proof-strength or hardness value must therefore not be used as a universal guarantee for every CuSn5 product.
For R310, Rm is 310-390 MPa and A50 is at least 45% up to 2.5 mm; for R400, Rm is 400-500 MPa, Rp0.2 at least 240 MPa and A50 at least 14%; for R490, Rm is 490-580 MPa, Rp0.2 at least 430 MPa and A50 at least 8%; for R550, Rm is 550-640 MPa, Rp0.2 at least 510 MPa and A50 at least 4%; for R630, Rm is 630-720 MPa, Rp0.2 at least 600 MPa and A50 at least 2%; for R690, Rm is at least 690 MPa and Rp0.2 at least 670 MPa. The R310 Rp0.2 maximum of 250 MPa is informative. R and H codes are alternative ordering conditions and must not be treated as one mandatory combined condition.
Typical Physical Properties
Typical density is about 8.85 g/cm³, modulus of elasticity about 120-121 GPa, thermal conductivity about 63-69 W/(m·K), thermal expansion about 17.8-18.2 × 10⁻⁶/K and electrical conductivity about 10 MS/m. These are typical references rather than guaranteed product-standard values.
Properties and Applications
CuSn5 combines high elasticity, good spring behaviour, fatigue strength, corrosion resistance, cold formability and solderability. Typical uses include contact springs, electrical and signal connectors, terminals, relay and switch components, clips, washers, stamped precision parts, diaphragms, bellows, Bourdon tubes and light-duty sliding elements.
Machinability is not the alloy’s principal advantage. For bushes, bearings or gears, product form, condition, contact pressure, speed, lubrication and counterface must be assessed together. Heavy-duty suitability should not be claimed solely from the alloy name.
Production and Supply Forms
CuSn5 / CW451K is principally supplied as cold-rolled strip and sheet, drawn wire, rod, profile and seamless tube. Depending on product form, EN 1652, EN 1654, EN 12163, EN 12166, EN 12167 and EN 12449 may apply.
CW451K is a wrought-product number. Cast parts of similar chemistry specially manufactured by Çorum Bronz must not be described as CW451K or EN 1652 compliant; they require a separate customer specification and actual chemical and mechanical test reports.
Standards and Comparable Grades
The principal European designation is CuSn5 / CW451K. UNS C51000 and JIS C5102 are close cross-references, but their composition limits and product conditions are not identical. ASTM B103/B103M covers flat products and rolled bar, ASTM B139/B139M covers rod, bar and shapes, and ASTM B159/B159M covers wire. C51000 is a UNS alloy number, not an ASTM standard.
CuSn5P is a former French/AFNOR comparison and PB102 a former British comparison. The CuSn5 designation under ISO 427:1983 is historical and the standard has been withdrawn. The 2.1018 number found in some sources was not verified consistently enough to include in the main equivalence table.
Technical Note
Final properties must be verified according to product form, thickness or diameter, R or H condition, rolling direction, surface condition and purchase specification. Design values must be confirmed by the current material certificate and producer test report.