CuZn25Al6Fe3Mn3

What Is CuZn25Al5Mn4Fe3?

CuZn25Al5Mn4Fe3 is a high-strength copper-zinc manganese bronze / special brass alloyed with aluminium, manganese and iron. Under EN 1982, the casting grade is CuZn25Al5Mn4Fe3-C / CC762S and the ingot grade is CuZn25Al5Mn4Fe3-B / CB762S. Çorum Bronz produces and supplies it under the trade name KUZRAL® 4.

Casting and Ingot Distinction

CC762S identifies finished or semi-finished cast products. CB762S is an ingot grade intended for remelting in casting production. Mechanical properties apply to CC762S castings, while the chemical limits of CC762S and CB762S are assessed separately.

Chemical Composition

For CC762S castings, Cu including Ni is 60.0-67.0%, Al 3.0-7.0%, Fe 1.5-4.0% and Mn 2.5-5.0%, with Zn as the remainder. Ni is limited to 3.0%, Pb to 0.20%, Sn to 0.20%, Si to 0.10%, P to 0.03% and Sb to 0.03%. In CB762S ingots, Cu including Ni is 60.0-66.0%, Al 4.0-7.0%, Fe 1.5-3.5% and Mn 3.0-5.0%.

Mechanical Properties

EN 1982 references use minimum values of Rm 750 MPa, Rp0.2 450 MPa, A 8% and 180 HBW for sand casting (GS); 750 MPa, 480 MPa, 8% and 180 HBW for permanent mould casting (GM); and 750 MPa, 480 MPa, 5% and 190 HBW for centrifugal (GZ) and continuous casting (GC). Final results may vary with section, specimen location and casting structure.

Typical Physical Properties

Manufacturer references indicate a density of approximately 7.8-8.2 g/cm³, specific heat of approximately 0.376 J/(g·K), thermal expansion of approximately 18.0 × 10⁻⁶/K, thermal conductivity of 45-55 W/(m·K) and electrical conductivity of 7-8 MS/m. These are typical reference values rather than guaranteed EN 1982 requirements.

Çorum Bronz Technical Assessment

KUZRAL® 4 combines high tensile and proof strength, high hardness and suitable wear resistance for machine components operating under very high static loads and low sliding speeds. Dynamic load, vibration, impact, lubrication, mating-surface hardness and operating temperature are evaluated according to project conditions.

Appropriate continuous lubrication and a hardened mating surface support service performance in plain-bearing applications. Graphite-plugged products are separate bearing solutions that combine the base alloy with solid lubricants.

Applications

Typical applications include bushings under very high static loads, low-speed plain bearings, slow-running worm wheels, bridge pins and bearings, hydraulic cylinder parts, high-pressure valve stems, cams, heavy-duty gears, wear plates and rolling-mill components.

Production Technology and Supply Forms

KUZRAL® 4 may be produced by sand, permanent mould, centrifugal and continuous casting. Supply forms include bronze tubes / hollow bars, round bars, flats, plates, bushing blanks and custom cast components manufactured to drawing.

Production, Sales and Supply by Çorum Bronz

Çorum Bronz manufactures standard and project-specific products in CuZn25Al5Mn4Fe3-C / CC762S. Available sizes, cut lengths, hollow products, round bars, flats and plates can be supplied through the Metal Market; custom production considers drawings, tolerances, casting processes and quality documentation.

Standards and Comparable Grades

The main European casting designation is CuZn25Al5Mn4Fe3-C / CC762S, with CuZn25Al5Mn4Fe3-B / CB762S as the related ingot. Former DIN designations are G-CuZn25Al5 / 2.0598.01, GK-CuZn25Al5 / 2.0598.02, GZ-CuZn25Al5 / 2.0598.03 and GB-CuZn25Al5 / 2.0608 for ingots. UNS C86300 / SAE 430B and BS 1400 HTB3 are close comparisons rather than exact equivalents.

Engineering Note

Material selection should consider static and dynamic loads, speed, lubrication, mating-surface hardness, temperature, corrosive environment, section and production method. Ammonia-containing environments and operating conditions involving stress-corrosion risk require separate assessment. Final product properties should be confirmed through the purchase specification, analysis certificate, mechanical testing and dimensional inspection.