Tin Bronzes

Our alloys

The range of bronzes we produce is traditionally among the most extensive available.

Our wide-ranging experience gained on the national market and our extensive export business justly allow us to be considered as valid partners for every type of utilisation. In this perspective we summarise hereunder our main productions, grouping them by prevalent deployment, with emphasis however on the fact that our plants regularly produce different alloys to client specification or according to standards and specifications from various Countries.
Our experienced technicians are at your disposal for any required service, in-depth analyses or study of new alloy or processing that may arise from the market or with clients.

Fields of application.

G – CuSn10 and G – CuSn12 are recommended for all fields in which plant resistance to wear and corrosion are demanded. Generally, they are destined for the construction of supports, shaft bushings, gearings coupled to steel feed screws and particularly suited to withstand use in corrosive or marine environments. As a result, therefore, they are widely used in the naval field and petrochemical industry (centrifugal pump casings and rotors, vacuum pumps).
G-CuSn10Zn2 and G-cuSn10Zn2Ni2 alloys, derived from the two traditional binary bronzes, replacing 2 or 4 units of stain with as many units of zinc, maintain their technological characteristics practically unchanged. Zinc in these percentages, in fact, does not noticeably modify the mechanical characteristics of either the original binary bronze, or its resistance to corrosion, which is kept at the same acceptable levels. Zinc’s strong deoxidising action facilitates foundry operations and makes these bronzes particularly suitable for sand casting. Suitable for shells of strongly loaded sliding bearings, naval and rolling mill shaft sleeves, thin-wall and complicated castings, pump casings and vessels subject to saturated steam up to 225°C. The addition of nickel to Cu – Sn – Zn alloys, in fact improves the mechanical characteristics in large-section castings in which higher traction braking loads are obtained, and in thinner-section castings, greater resistance to abrasion and corrosion is obtained.
CuSn7Zn2Pb3 and industrial 86/14 constitute a variant of Cu – Sn – Zn alloys, with a reduced lead content being added to increase machine tool workability and to improve foundry quality. It has been proven that around 3% of lead content is generally sufficient to ensure good sealing of pressure from columnar-structure casts. Compared with other bronzes, alloys in this class, that distinguish themselves for economic reasons at the same tin content, are largely used in the production of wear-resistant and pressure-proof casts as well as mechanically stressed parts or elements subjected to corrosion.
G- CuSn5Zn5Pb5 and CuSn7Zn4Pb7 are alloys particularly suited for sealed castings, thanks to considerable quantities of zinc content and even more of lead, owing to their low melting point. Furthermore, they afford machine tooling workability that can be compared with that of dry brass. Typical applications of these alloys are in hydraulic and pneumatic valves, pump casings and rotors and for slightly acid waters as well as for wine-making processes, flanges and fittings for bearings, machine parts for the paper industry, architectural bronze and statue castings.

Chemical Composition %

Alloy designation Cu Sn Pb Zn Ni Fe Sb S P Mn
G – Cu Sn10 UNI 7013 resto 9 – 11 0,8 max 0,5 max 0,7 max 0,2 max 0,2 max 0,1 max 0,05 max 0,2 max
G – Cu Sn12 UNI 7013 resto 11 – 13 1 max 0,5 max 0,7 max 0,2 max 0,2 max 0,1 max 0,05 max 0,2 max
G – Cu Sn10 Zn2 resto 8,5 – 11 1,3 max 1 – 3 1 max 0,2 max 0,3 max 0,1 max 0,05 max 0,2 max
G – Cu Sn10 Zn2 Ni2 resto 9 – 11 1 max 1,5 – 2,5 1,8 – 2,5 0,2 max 0,3 max 0,1 max 0,05 max 0,2 max
86 / 14 Industriale resto 9 – 11 1 – 3 1 – 3 1 max 0,30 max 0,30 max 0,1 max 0,05 max 0,2 max
85/5/5/5 UNI 7013 resto 4 -6 4 – 6 4 – 6 2 max 0,3 max 0,4 max 0,1 max 0,05 max 0,1 max
Cu Sn5 Zn5 Pb5 (CB491K) 83 – 86,5 4,2 – 6 4,2 – 5,8 4,5 – 6,5 2 max 0,25 max 0,25 max 0,1 max 0,03 max 0,1 max
Cu Sn7 Zn4 Pb7 (CB493K) 81 – 84,5 6,2 – 8 5,2 – 8 2,3 – 5 2 max 0,20 max 0,30 max 0,08 max 0,03 max 0,1 max
Cu Sn5 Zn5 Pb2 (CB499K) 84 – 87,5 4,2 – 6 3 max 4,5 – 6,5 0,6 max 0,3 max 0,1 max 0,04 max 0,03 max 0,1 max

Physical properties

Commercial designation Density Kg/dm³ Electrical conductivity % IACS Machinability rating % (free-machining brass = 100) Linear shrinkage % Optimum casting range °C Lower melting point °C
G – Cu Sn10 UNI 7013 8,78 10 – 11 40 1,5 – 1,8 1000 – 1100 845
G – Cu Sn12 UNI 7013 8,75 9 – 10 40 1,5 – 1,8 1070 – 1170 830
G – Cu Sn10 Zn2 8,70 10 – 11 40 1,5 – 1,8 1100 – 1250 848
G – Cu Sn10 Zn2 Ni2 8,75 10 – 11 40 1,5 – 1,8 1100 – 1200 865
86 / 14 Industriale 8,8 9 – 10 70 1,5 – 1,8 1070 – 1170 840
85/5/5/5 UNI 7013 8,8 13 – 15 90 1,3 – 1,6 1070 – 1230 854
Cu Sn5 Zn5 Pb5 (CB491K) 8,8 13 – 15 90 1,3 – 1,6 1070 – 1230 854
Cu Sn7 Zn4 Pb7 (CB493K) 8,9 11 – 12 90 1,5 – 1,8 1100 – 1250 854
Cu Sn5 Zn5 Pb2 (CB499K) 8,7 12 – 14 80 1,4 – 1,7 1100 – 1250 855

Mechanical properties (sand casting)

Commercial designation Tensile strenght R N/mm² Yield strenght Rr (0,2) N/mm² Elongation A % Hardness Brinell HB
G – Cu Sn10 UNI 7013 240 – 280 120 – 150 12 – 17 60 – 75
G – Cu Sn12 UNI 7013 240 – 290 130 – 160 7 – 12 80 – 95
G – Cu Sn10 Zn2 240 – 280 120 – 140 12 – 15 65 – 80
G – Cu Sn10 Zn2 Ni2 240 – 300 120 – 150 11 – 15 70 – 85
86 / 14 Industriale 240 – 290 130 – 180 6 – 11 75 – 90
85/5/5/5 UNI 7013 200 – 240 80 – 100 12 – 18 60 – 70
Cu Sn5 Zn5 Pb5 (CB491K) 200 – 240 80 – 100 12 – 18 60 – 70
Cu Sn7 Zn4 Pb7 (CB493K) 210 – 250 90 – 120 12 – 18 60 – 75
Cu Sn5 Zn5 Pb2 (CB499K) 200 – 240 90 – 110 13 – 19 60 – 75

We have a large stock of alloys that allow us to respond promptly to the requests of all our customers.

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Our alloys

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