C90300 is a “GREEN” non-leaded alloy
Tin Bronze – Navy G QQC-390B Type II and Type III
CDA 903 SAE 620 88-8-0-4 ASTM B505
Bunting continuous cast bronze bars of C90300 give superior quality and performance. Continuous casting achieves a high density grain structure, free of porosity, resulting in a reduction of tool wear and component rejects.
Solid bars are stocked 13" increments and 105" lengths, and are available in other lengths and nonstandard sizes. Consider bars for use when you need special bearings, bearings for prototypes, or for emergency repairs.
Typical Properties: (Not to be used for specification purposes.)
Copper: 86.00 – 89.00%
Tin: 7.50 – 9.00%
Lead: 0.30% max.
Zinc: 3.00 – 5.00%
Physical Properties: Continuous Cast
Tensile Strength PSI: 44,000 min
Yield Strength PSI: 22,000 min.
Elongation: 18% min.
Brinell Hardness (500 kg load): 70 typical
Machinability Rating: 30
Minimum Operating Temperature: -450°F
Maximum Operating Temperature: 550°F
C90300 is used for bearings, seal rings, gears, piston rings, pump impellers, steam fittings, and valve components. C90300 has good wear resistance but should be used with hardened steel shafts (300-400 HB). Due to the lack of lead, this material requires constant lubrication, generally grease.