What H62 Brass Is
H62 is the Chinese designation for the wrought two-component brass that contains about 62 % copper with zinc as the balance, and it is the general-purpose brass of the sheet, strip, tube and rod trade. Under GB/T 5231 the grade is written H62 and its composition is CuZn38; the specification limits copper to 60.5-63.5 %, holds lead to 0.08 % maximum, iron to 0.15 % maximum and total impurities to 0.5 % maximum, with zinc making up the remainder. In UNS terminology the nearest wrought designation is C28000, whose composition range of 59.0-63.0 % copper brackets the GB range for H62, so the two are commonly offered interchangeably after the other requirements have been checked.
The reason H62 holds such a large share of general engineering work is its balance. It cold works well, solders and brazes easily, resists atmospheric and fresh-water corrosion, and still develops useful strength when cold rolled or drawn. It sits between the more ductile 65/35 and 70/30 brasses and the stronger, less ductile 60/40 compositions, which makes it a sensible default when a design needs both formability and strength.
Chemical Composition
| Element | Content | Note |
|---|---|---|
| Copper | 60.5-63.5 % | Matrix element |
| Zinc | Remainder, roughly 36.5-39.5 % | Principal alloying element |
| Lead | 0.08 % max | Kept low, so the grade is not a free-machining brass |
| Iron | 0.15 % max | Residual element |
| Total impurities | 0.5 % max | Protects ductility and surface quality |
Physical Properties
| Property | Typical value | Practical meaning |
|---|---|---|
| Density | 8.43-8.47 g/cm³ | About five percent lighter than pure copper |
| Electrical conductivity | roughly 22-28 % IACS | Adequate for current-carrying hardware, far below pure copper |
| Thermal conductivity | 115-120 W/(m·K) | Suits heat dissipation parts and radiator components |
| Coefficient of linear expansion | about 20.6 × 10⁻⁶ per °C | Similar to steel, which reduces joint stress in mixed assemblies |
| Melting range | approximately 900-940 °C | Good casting fluidity in the liquid region |
Mechanical Properties and Tempers
The mechanical values of H62 depend more on temper than on chemistry, so a purchase order has to name the temper and not the grade alone. Soft annealed material is used where the part must be deep drawn or bent; half-hard and hard tempers are used where strength and wear resistance dominate.
| Temper | Tensile strength | Elongation | Hardness |
|---|---|---|---|
| Soft annealed O60 | about 340-430 MPa | 25-45 % | about 80-110 HB |
| Half hard H02 | about 430-540 MPa | 10-25 % | about 110-140 HB |
| Hard H04 and above | about 540-650 MPa | 3-10 % | up to about 150 HB |
Annealing is carried out between roughly 550 °C and 650 °C to remove the work hardening introduced by rolling or drawing. Over-annealing must be avoided, because it coarsens the grain and weakens the surface finish that subsequent cold rolling depends on.
How H62 Compares with Neighbouring Brasses
Against 70/30 and 65/35 brass: H62 is stronger and cheaper per unit of strength but less ductile, so deep drawing and severe bending become harder.
Against 60/40 compositions: H62 is more ductile and easier to cold form, with only a modest loss of strength.
Against leaded free-machining brass such as C36000: H62 contains at most 0.08 % lead, so it machines with long chips and poorer surface finish. Parts that are turned in volume should use a leaded grade instead.
Against phosphor bronze: H62 gives up both strength and corrosion resistance in marine and spring service, but costs less and forms more easily.
Typical Applications and Fabrication Notes
Architectural and decorative sheet, strip and extruded profiles
Heat exchanger shells, radiators, condenser plates and heat dissipation parts
Electrical hardware, terminals, connector bodies and current-carrying brackets
Fasteners, rivets, washers, pins and stamped components
Plumbing fittings, valves, and general tube and rod stock
H62 solders and brazes without difficulty and can be joined by resistance welding. Stress relief after heavy cold forming is worth specifying for parts that will see ammonia or humidity, because unstressed parts resist season cracking much better than stressed ones. In chloride-bearing service the alloy is normally acceptable, but in flowing seawater or in ammonia-bearing condensate the dezincification risk rises and a tin brass or cupro-nickel grade should be chosen.
Surface finish is usually ordered in one of three conditions: mill finish for parts that will be painted or further processed, bright annealed for visible components and for subsequent plating, and brushed finish for decorative panels. Cut edges should be deburred before plating so that the coating covers the full section.
Frequently Asked Questions
Q: What does H62 mean in the brass designation?
The number gives the nominal copper content in mass percent, so H62 is a copper-zinc brass with about 62 % copper and zinc as the balance, written as CuZn38 in compositional form.
Q: Is H62 brass the same as C28000?
The nearest wrought UNS designation is C28000, whose copper range of 59.0-63.0 % brackets the GB/T 5231 range for H62. Because the limits differ slightly, the equivalence must be confirmed against the requirements of the specific part before substitution.
Q: Can H62 brass be used for machining?
It machines, but the lead limit of 0.08 % maximum means long chips and moderate surface finish. Volume turned parts are better produced from a leaded brass such as C36000.
Q: Which temper should be ordered for a bent or deep-drawn part?
Soft annealed O60, because it carries 25-45 % elongation. Half-hard and hard tempers are chosen for flat parts that need stiffness and wear resistance rather than severe forming.
Q: Is H62 suitable for seawater service?
Only in mild conditions. The alloy can dezincify in chloride-bearing water and is sensitive to ammonia, so flowing seawater or condensate duties should use an inhibited tin brass or a cupro-nickel grade.
Q: What annealing temperature removes work hardening?
Normal annealing of H62 is carried out between about 550 °C and 650 °C. The exact point is chosen to restore ductility without growing the grain, which would degrade surface finish and fatigue behaviour.
