Reference guide

Continuous cast

The lead content in high-leaded tin bronze alloys is between 7 percent and 30 percent. This group of alloys is free cutting and retains favorable thermal conductivity and good lubricity due to the presence of lead. High-leaded tin bronzes are ideal for bearing applications where there could be a loss of the lubrication boundary. These alloys perform extremely well in unforgiving environments where foreign matter may be present, such as dirt and other foreign materials. They are able to envelope foreign matter due to their malleable nature and, in doing so, protect the wear surface of a coupled part.


Product description: High-leaded tin bronze
Solids: 1/2" to 13" O.D.
Tubes: 1" to 16" O.D.*
Rectangles: Up to 20"
Standard lengths: 144"
Shape/Form: semi-finished, mill stock or near-net shapes, anode, bar stock, billet/bloom, squares, hex, plate, profile or structural shape, flats/rectangular bar

 *Consult mill for wall thickness

Typical uses

Builders hardware: brackets
Fasteners: nuts, washers for engines
Industrial: applications requiring acid resistance to sulphite fluids, bearing plates, bearings, bushings, bushings for high speed and heavy pressure, corrosion-resistant castings, crank shafts, high speed/heavy load bearings, impellers, machine parts, parts for steel mill maintenance, pressure-tight castings, pumps, slide guides for steel mills
Marine: large bearings for ships

Similar or equivalent specification

CDA ASTM SAE AMS Federal Military Other Desc
C93700 B505
  QQ-C-390, E10 MIL-B-11553, Comp 23 Bearing Bronze;
80-10-10 Bronze

Chemical composition

Cu% Pb% Sn% Zn% Fe%1 P% Ni%2 Al% S% Sb% Si%
Chemical composition according to ASTM B505/B505M-23

1Fe shall be 0.35% max., when used for steel-backed bearings.   2Ni value includes Co.
Note: Cu + sum of named elements, 99.0% min. Single values represent maximums.


Copper alloy UNS No. Machinability rating Density (lb/in3 at 68 °F)
C93700 80 0.32

Mechanical properties

Mechanical properties according to ASTM B505/B505M-23
Tensile strength, min Yield strength, at 0.5% extension under load, min Elongation, in 2 in. or 50 mm min Brinell hardness (500 kg load) Remarks
ksi MPa ksi MPa % typical BHN  
35 241 20 138 6 60  

Physical properties

Physical properties provided by CDA
  US Customary Metric
Melting point - liquidus 1705 °F 929 °C
Melting point - solidus 1403 °F 762 °C
Density 0.32 lb/in3 at 68 °F 8.86 gm/cm3 at 20 °C
Specific gravity 8.86 8.86
Electrical conductivity 10% IACS at 68 °F 0.059 MegaSiemens/cm at 20 °C
Thermal conductivity 27.1 Btu/sq ft/ft hr/°F at 68 °F 46.9 W/m at 20 °C
Coefficient of thermal expansion 68-392 10.3 · 10-6 per °F (68°-392 °F) 17.8 · 10-6 per °C (20°-200 °C)
Specific heat capacity 0.09 Btu/lb/°F at 68 °F 377.1 J/kg at 20 °C
Modulus of elasticity in tension 11000 ksi 75800 MPa
Incipient Melting 600 °F 316 °C
Magnetic Permeability 1 1

Fabrication properties

Fabrication properties provided by CDA
*Since brazing is performed within the hot-short range, strain must be avoided during brazing and cooling.
Technique Suitability
Soldering Good
Brazing* Good
Oxyacetylene welding Not recommended
Gas shielded arc welding Not recommended
Coated metal arc welding Not recommended
Machinability rating 80

Thermal properties

Thermal properties provided by CDA
*Temperature is measured in fahrenheit.   **For stress relief, solution treatment and annealing - time is measured in hours/inch of thickness. For precipitation heat treatment - time is measured in hours.
Treatment Value* Time**
Stress relief 500  
Solution treatment   0

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