CZ136

CZ136 (governed by British Standards BS 2874 for rods and sections, BS 2872 for forging stock, and harmonized under European specifications as EN 12164 / EN 12165 CW720R) is an engineered, leaded (α + β) duplex brass classified as a Manganese Brass or Medium High-Tensile Brass. In earlier iterations of BS 2872, related compositions were cataloged under CZ123. Formulated with 57.0% to 59.0% Copper, 0.8% to 1.8% Manganese (Mn), and a balanced 0.5% to 1.5% Lead (Pb) addition, CZ136 occupies a functional position between standard forging brass (CZ122) and heavy-duty manganese bronzes (CZ114/CZ115). Manganese acts as a matrix strengthener and grain refiner without impairing hot plasticity, while lead ensures controlled chip formation during secondary CNC machining.