28
Cu
Copper
Kalan
CuSn6
CuSn6P | Phosphor Bronze | EN CuSn6 / CW452K
KUPTİN® P6 (CuSn6 / CW452K) is a phosphor tin bronze combining high elasticity, fatigue strength, cold formability and corrosion resistance.
- Alloy
- CuSn6
- EN
- CuSn6 / CW452K
- Former DIN
- CuSn6 / 2.1020
- Close UNS
- C51900 (not identical)
- Historical name
- CuSn6P (AFNOR)
- Density
- 8.8 g/cm³
01. Chemical Composition (%)
50
Sn
Tin
%5,50 – 7,00
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 | R350 350-420; R420 420-520; R500 500-590; R560 560-650; R640 640-730; R720 ≥720 | EN 1652; flat product and temper dependent |
| 0.2% Proof Strength Rp0.2 | MPa | R350 ≤300*; R420 ≥360; R500 ≥460; R560 ≥530; R640 ≥610; R720 ≥690 | EN 1652; *informative value |
| Elongation A50 | % | R350 ≥45; R420 ≥17; R500 ≥8; R560 ≥5; R640 ≥3 | EN 1652; flat product |
| Hardness | HV | H080 80-110; H125 125-165; H160 160-190; H180 180-210; H200 200-230; H220 ≥220 | Informative values; temper dependent |
| Density | g/cm³ | approximately 8.8 | Typical value |
03. Applications
- Contact springs
- Electrical and signal connectors
- Terminals and contact blades
- Relay and switch components
- Press-fit and compliant contact pins
- Precision stamped and bent parts
- Springs and elastic fasteners
- Membranes and diaphragms
- Bourdon tubes and flexible metal tubes
- Thin-section wear and moving 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 temper. Special cast products must not be represented as CW452K or EN 1652 compliant; they require a separate customer specification and actual 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 CuSn6P?
CuSn6P is a wrought phosphor bronze containing approximately 6% tin and controlled phosphorus. Its correct EN alloy designation is CuSn6 and its material number is CW452K. CuSn6P is principally a historical French/AFNOR designation. Tin contributes strength and corrosion resistance, while phosphorus supports deoxidation, hardness and wear behaviour.
Chemical Composition
For CuSn6 / CW452K, Sn is 5.5-7.0% 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 CuSn6 vary significantly with product form, thickness and degree of cold work. EN 1652 flat-product references cover strength conditions from R350 to R720, with tensile strength rising from the 350 MPa level to 720 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 CuSn6 product.
For R350, Rm is 350-420 MPa and A50 is at least 45%; for R420, Rm is 420-520 MPa, Rp0.2 at least 360 MPa and A50 at least 17%; for R500, Rm is 500-590 MPa, Rp0.2 at least 460 MPa and A50 at least 8%; for R560, Rm is 560-650 MPa, Rp0.2 at least 530 MPa and A50 at least 5%; for R640, Rm is 640-730 MPa, Rp0.2 at least 610 MPa and A50 at least 3%; for R720, Rm is at least 720 MPa and Rp0.2 at least 690 MPa. Hardness values are informative condition-related references.
Typical Physical Properties
Typical density is about 8.8 g/cm³, modulus of elasticity about 115-118 GPa, thermal conductivity about 75 W/(m·K), specific heat about 0.377 J/(g·K), thermal expansion about 18-18.5 × 10⁻⁶/K and electrical conductivity in annealed temper about 9-10 MS/m. These are typical references rather than guaranteed product-standard values.
Properties and Applications
CuSn6 combines high elasticity, good spring behaviour, fatigue strength, wear and corrosion resistance, cold formability and solderability. Typical uses include contact springs, electrical and signal connectors, terminals, relay and switch components, press-fit pins, precision stamped and bent parts, spring elements, membranes, diaphragms, Bourdon tubes and flexible metal tubes.
Machinability is not the alloy’s principal advantage. For bushes, bearings or gears, product form, temper, contact pressure, speed, lubrication and counterface must be assessed together. Heavy-duty gear or bearing suitability should not be claimed solely from the alloy name.
Production and Supply Forms
CuSn6 / CW452K 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.
EN 1982 covers ingots and castings, whereas CW452K is a wrought-product number. Cast parts of similar chemistry specially manufactured by Çorum Bronz must not be described as CW452K 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 CuSn6 / CW452K and the former German material number is 2.1020. UNS C51900 and JIS C5191 are close cross-references, but their limits and product conditions are not identical. ASTM B103/B103M is a product specification covering C51900 plate, sheet, strip and rolled bar; C51900 is a UNS alloy number, not an ASTM standard.
CuSn6P is a former French/AFNOR designation and PB103 a historical British comparison. CuSn6 under ISO 427:1983 is historical and the standard has been withdrawn. CW451K, C90700, EN 1982 and BS 1400 must not be used as counterparts in the wrought CuSn6/CW452K grade table.
Technical Note
Final properties must be verified against product form, thickness or diameter, R/H temper, rolling direction, surface condition and order standard. Design values should be confirmed by the current material certificate and producer test report.