Cast tin bronzes and leaded tin bronzes

Dr. Dmitri Kopeliovich

According to the Unified Numbering System (UNS):

Tin Bronzes are copper alloys, containing 7-19% of tin (Sn) as the major alloying element. Cast Tin Bronzes (Tin Bronze, Gun Metal, Tin Bronze 65, Nickel Gear Bronze) are designated with the numbers from C90000 through C91999.

Leaded Tin Bronzes are copper alloys, containing 5-16% of tin (Sn) and up to 30% of lead (Pb) as the major alloying elements and up to 4% of zinc (Zn) and up to 1.6% of nickel (Ni) as additional alloying elements. Cast Leaded Tin Bronzes (Naval M Bronze, Leaded Tin Bronze, Bearing Bronze, Anti-Acid Metal, Soft Bronze) are designated with the numbers from C92000 through C94500 (including High Leaded Bronzes).

Tin Bronzes containing up to 13% of tin have mono-phase structure (α-phase).

Such alloys possess relatively high ductility.

Alloys, containing more than 13% of tin, have significant amount of brittle δ-phase.

Ductility of these Tin Bronzes is very low.

Lead is added to the alloys (Leaded Tin Bronzes) for improvement their machinability and increasing pressure tightness. Mechanical strength and ductility of the Leaded Tin Bronzes is lower than those of Tin Bronzes.

Cast High Leaded Tin Bronzes (C93000 – C94500) contain more lead (10-30%), than Leaded Tin Bronzes. Cast High Leaded Tin Bronzes are used as sliding bearing materials. High content of lead, dispersed as separate phase throughout copper-tin matrix, imparts anti-friction properties to the alloy.

Cast Tin Bronzes and Leaded Tin Bronzes are used for manufacturing sleeve bushings,pump impellers, piston rings, electrical connectors, valve bodies, water conditioners, gears, engine bearings, pump bodies, pump parts for acid mine water, railroad parts.

UNS Designation	Trade mark	Sn,%	Pb,%	P,%	Zn,%	Ni,%	Cu,%
C90300	Tin Bronze	7.5-9.0	0.30 max.	0.05 max.	3.0-5.0	1.0 max.	86-89
C90500	Gun Metal	9.0-11.0	0.30 max.	0.05 max.	1.0-3.0	1.0 max.	86-89
C90700	Tin Bronze, 65	10.0-12.0	0.50 max.	0.05 max.	0.50 max.	0.50 max.	88-90
C91700	Nickel Gear Bronze	11.3-12.5	0.25 max.	0.30 max.	0.25 max.	1.2-2.0	88-90
C92200	Naval M Bronze	5.5-6.5	1.0-2.0	0.05 max.	3.0-5.0	1.0 max.	86-90
C92700	Leaded Tin Bronze	9.0-11.0	1.0-2.5	0.25 max.	0.70 max.	1.0 max.	86-89
C93700	Bearing Bronze	9.0-11.0	8.0-11.0	0.10 max.	0.80 max.	0.50 max.	78-82
C93800	Anti-Acid Metal	4.5-6.0	23.0-27.0	0.10 max.	0.80 max.	0.50 max.	78-82
C94300	Soft Bronze	9.0-11.0	8.0-11.0	0.08 max.	0.80 max.	1.0 max.	78-82

(Materials Data)

• Cast copper alloy C90300 (Tin Bronze)
• Cast copper alloy C90500 (Gun Metal)
• Cast copper alloy C90700 (Tin Bronze, 65)
• Cast copper alloy C91700 (Nickel Gear Bronze)
• Cast copper alloy C92200 (Naval M Bronze)
• Cast copper alloy C92700 (Leaded Tin Bronze)
• Cast copper alloy C93700 (Bearing Bronze)
• Cast copper alloy C93800 (Anti-Acid Metal)
• Cast copper alloy C94300 (Soft Bronze)

to top

---

• Cast Coppers and high copper alloys
• Cast brasses
• Cast manganese bronzes
• Cast silicon bronzes and silicon brasses
• Cast aluminum bronzes
• Cast copper-nickel alloys and Nickel Silvers
• Spinodal Bronzes
• Cast copper-lead alloys
• Cast copper special alloys
• Copper based bearing materials
• Wrought phosphor bronzes
• Classification of copper alloys
• Temper designation of copper alloys
• Treatment of molten copper alloys

to Metals
to Copper alloys