Overview of H62 Brass
H62 is one of the most widely used brass grades in China, designated in GB/T 5231 as a copper zinc alloy with a copper content of 60.5 to 63.5 percent and zinc as the balance. The material is often compared to UNS C27000 brass in international trade. Because its structure contains both alpha and beta phases at room temperature, H62 offers a practical combination of strength, hardness and formability that suits high volume manufacturing of mechanical parts.
Chemical Composition
The nominal composition is 62 percent copper and 38 percent zinc. Impurities are controlled with iron, lead and other elements each limited to small maximum values defined by the standard. The lead content can be adjusted to produce free cutting grades for automatic lathe machining, while standard grades keep lead low for good cold working and soldering.
Mechanical Properties
In the soft annealed condition H62 has a tensile strength of about 330 MPa with elongation of roughly 40 percent. Cold working to the half-hard and hard conditions raises the tensile strength to 370 to 420 MPa and 410 to 630 MPa respectively, with a corresponding reduction in ductility. Hardness follows the same pattern, from about 60 HRF in soft condition up to values suitable for wear resistant parts.
Available Forms and Tempers
H62 is supplied as sheet, strip, foil, tube, rod, bar and wire, allowing manufacturers to choose the most economical starting form. Temper designations follow Chinese practice with M for soft annealed, Y2 for half-hard and Y for hard condition. Strip and sheet are commonly used for stamping and deep drawing, rod and wire for turned parts and fasteners, and tube for condensers and heat exchange equipment.
Processing Characteristics
H62 has good hot workability at temperatures around 700 to 800 degrees Celsius and excellent cold workability in the annealed condition. It can be machined at moderate speeds, and its chips break more easily than those of high copper brasses. Brazing, soldering and silver soldering are straightforward, and the alloy can be electroplated with nickel or chromium for decorative and wear resistant finishes.
Typical Applications
Typical applications include radiator tanks and cores, fasteners, nuts and bolts, rivets, hardware fittings, locks, watch parts, zippers, plumbing fittings, instrument components and electrical terminal parts. The alloy is also used for deep drawn shells and stamped components in the automotive and electronics industries.
Frequently Asked Questions
What does the number 62 mean in H62? The number indicates the nominal copper content of about 62 percent, with zinc forming the balance of the alloy.
Is H62 the same as C27000? H62 and UNS C27000 have similar nominal compositions and properties and are frequently treated as equivalents for design and procurement.
Can H62 be deep drawn? Yes, in the annealed condition H62 can be deep drawn into shells and cups, although alloys with higher copper content such as H68 are preferred for very severe draws.
Does H62 resist corrosion in water? H62 resists atmospheric corrosion and fresh water well, but it may be subject to dezincification in certain aggressive waters; inhibited grades or higher copper alloys are used where this is a risk.
Is H62 suitable for machining? Standard H62 machines acceptably, and leaded versions provide improved chip control and surface finish for automatic screw machines.
