Phosphor Bronze Wire

At SMI, we manufacture phosphor bronze wires, an alloy of copper, tin and phosphorous. Our phosphor bronze wires possess excellant spring qualities, high corrosion resistance and good formability. While tin increases the strength of the material, phosphor increases its corrosion resistance and stiffness. Hence phosphor bronze, based on its varying content of tin are used in various electrical and industrial applications.

Alloy name and chemical composition

Alloy CSL Alloys ISO German USA Chemical composition
Phosphor Bronze PB 1% IS 7608, IS7611 & IS7811 Grade I, II, III & IS10710 Grade I & II C50500 0.5-1.5% 0.02-0.4% Rem.
PB 4% CuSn4 C51100 C51100 3.5-4.5% 0.02-0.4% Rem.
PB 5% CuSn5 C51000 C5102 4.5-5.5% 0.02-0.4% Rem.
PB 6% CuSn6 C51900 C5191 5.5-7.0% 0.02-0.4% Rem.
PB 8% CuSn8 C52100 C5210 7.5-9.0 % 0.02-0.4% Rem.


Electrical springs and connectors,switch parts, fasteners, machinery, washers, cold headed parts, wire brushes, etc