C90300 Tin Bronze, also known as Navy G and SAE 620, is a copper base that is alloyed with zinc and tin.  C903 offers excellent corrosion resistance with high wear resistance and low coefficient of friction.  CDA 903 Gear Bronze is well suited for applications involving high loads and low speeds.  C903 Tin Bronze is available as centrifugal cast, continuous cast and sand cast.  CDA
903 Navy G bronze has a wide variety of uses, including bushings, bearings, gear blanks, pump bodies, valve bodies and steam fittings.

Marmetal stock C90300 Tin Bronze in cast solid rounds.

Specifications for for C90300 Tin Bronze

ASTM MILITARY
Centrifugal Cast ASTM B271 QQ-C-390
Continuous Cast ASTM B505 QQ-C-390
Sand Cast ASTM B548 QQ-C-390

Mechanical Properties for C90300 Tin Bronze

Form Specification Tensile, min ksi (MPa) Yield, min ksi (MPa) Elongation in 2”, % min
Centrifugal Cast ASTM B271 40 (276) 18 (124) 20
Continuous Cast ASTM B505 44 (303) 22 (152) 18
Sand Cast ASTM B584 40 (276) 18 (124) 20
Compositions for C90300 Tin Bronze

COMMERCIAL
UNS No. Copper Tin Lead Zinc Nickel incl. Cobalt Iron Antimony Sulfur Phosphorus Aluminum Silicon
C90300 86.0-89.0 7.5-9.0 0.30 max 3.0-5.0 1.0 max 0.20 max 0.20 max 0.05 max 0.05 max 0.005 max 0.005 max
QQ-C-390
UNS No. Copper Tin Lead Zinc Nickel incl. Cobalt Iron Antimony Sulfur Phosphorus Aluminum Silicon
C90300 86.0-89.0 7.5-9.0 0.30 max 3.0-5.0 1.0 max 0.20 max 0.20 max 0.05 max 0.05 max 0.005 max 0.005 max
Physical Properties for for C90300 Tin Bronze

Density @ 68o F 0.318 lb/in3
Melting Range 1570-1832o F
Casting Yield Medium
Drossing Low
Effect on Section Size High
Fluidity Medium
Gassing Medium
Machinability rating (C360 = 100) 30
Brazing Good
Soldering Excellent
Gas-shielded arc welding Fair
Oxy-acetylene welding Fair
Coated metal-arc welding Fair
Applications for C90300 Tin Bronze

* Bushings
* Bearings
* Gear Blanks
* Pump Bodies
* Valve Bodies
* Steam Fittings
* Piston Rings
* Pump Impellers
* Seal Rings
* Worm Wheels