What Is H96 Copper Alloy?
H96 copper alloy is a copper-zinc brass whose copper content is nominally 96 percent, with zinc making up the remainder of the composition. The designation comes from the Chinese material system, where the letter H identifies brass and the number records the nominal copper content, so H96 sits close to the copper end of the brass series and far away from the stronger, zinc-rich duplex grades.
The material is important in practice because it behaves more like pure copper than like a conventional brass. Its single-phase alpha structure gives very high ductility, high electrical and thermal conductivity and good corrosion resistance in atmospheric and fresh water service. It is deliberately not a high-strength alloy: strength is sacrificed in exchange for formability and conductivity, and designers who need strength choose a lower copper brass such as H62 or H68 instead.
Cross-system identification is the first thing to settle when this grade is specified, because the same nominal composition is named differently in each system. The closest UNS equivalent is the gilding brass composition C21000 at about 95 percent copper, while the European designation for the same family is CuZn5 or CuZn4. Composition limits, impurity limits and temper definitions must be taken from the standard edition quoted on the enquiry, since the tolerances are not identical between systems.
Designation and Position in the Brass Family
Placing H96 among its neighbours clarifies what it can and cannot do. As copper content falls and zinc rises, strength and hardness increase while ductility, conductivity and corrosion resistance fall.
| Grade | Nominal copper content | Character | Typical use |
|---|---|---|---|
| H96 | About 96 percent | Highest ductility, highest conductivity, lowest strength | Deep drawing, conductivity parts, decorative strip |
| H90 | About 90 percent | Very good ductility, good conductivity | Strip, pressing, heat transfer parts |
| H80 | About 80 percent | Good ductility with more strength | Sheet, strip, hardware |
| H68 | About 68 percent | Balanced strength and ductility | Deep-drawn cartridge-type components |
| H62 | About 62 percent | Higher strength, duplex tendency | Structural and machined parts |
The table shows a continuous trend rather than a set of unrelated materials, and it explains why H96 is chosen for conductivity and severe forming work while the lower copper brasses are chosen for mechanical strength. Because H96 has no beta phase, it also cannot be strengthened by heat treatment; the only strengthening mechanisms available are cold work and the natural effect of the composition itself.
Composition and Impurity Control
The grade is defined by a high copper content, zinc as the balance and tightly restricted impurities. Residual elements are the main risk to performance because they reduce conductivity and can impair hot and cold workability.
Copper forms the base and sets the conductivity, colour and corrosion behaviour of the alloy.
Zinc is the alloying addition and the reason the material is a brass rather than a pure copper.
Iron is limited because it raises hardness and lowers electrical conductivity.
Lead is limited because it embrittles the material during hot working.
All other impurities are held to the individual and total limits given in the applicable grade table.
Where the material is destined for electrical service, the supplier should be asked for the analysed conductivity as well as the chemistry, because two heats within the same composition range can differ measurably in conductivity if impurity levels differ.
Properties of H96 Copper Alloy
H96 combines the conductivity of copper with the workability of a low-zinc brass.
| Property | Behaviour |
|---|---|
| Crystal structure | Single-phase alpha brass, face-centred cubic |
| Strength and hardness | Low compared with other brasses, higher than pure copper |
| Ductility and toughness | Excellent, suited to severe cold forming and deep drawing |
| Electrical conductivity | High, approaching the conductivity of pure copper |
| Thermal conductivity | High, suitable for heat transfer and heat dissipation parts |
| Corrosion resistance | Good in atmosphere and fresh water, limited in strong acids, alkalis and hot humid conditions |
| Machinability | Poor, long chips require free-cutting grades for automatic machining |
| Colour | Golden with a warm tone, becoming redder as copper content rises |
The numerical values attached to these properties are always temper dependent. An annealed strip will show maximum elongation and conductivity, while a heavily rolled strip will show higher tensile strength, lower elongation and slightly reduced conductivity. Temper must therefore be specified together with the mechanical and electrical requirements.
Processing, Welding and Forming
H96 is among the most forgiving copper alloys to fabricate. It cold rolls, deep draws, bends, spins and flattens readily, and it can be hot worked over a practical temperature range. Because it work hardens steadily, heavy forming sequences should be planned with intermediate anneals, and the annealed temper should be specified whenever the first operation involves large deformation.
Joining behaviour is good. Soft soldering, silver brazing and resistance welding are all used, and gas tungsten arc welding is practical where thicker sections must be joined. Zinc volatility means that fume extraction and controlled heat input are advisable, and the filler metal should be selected for the service environment rather than simply matched to colour.
Two cautions apply during processing. First, contact with ammonia or ammonium compounds should be avoided where the finished part carries residual tensile stress, since stress corrosion cracking can occur in high-copper brasses under those conditions; a stress relief anneal removes the risk. Second, contamination from iron tools and grinding dust should be removed before the part enters wet or outdoor service, because embedded particles become local corrosion initiation sites.
Applications of H96 Copper Alloy
The property set directs the alloy into applications where conductivity, formability or colour matters more than strength.
Electrical and electronic hardware: terminals, connector strip, shielding and current-carrying contacts.
Heat transfer components: radiator fins, heat sinks, heat exchanger strip and cooling elements.
Deep-drawn and stamped parts: caps, shells, eyelets and decorative pressings.
Architectural and decorative metalwork where the golden colour and durability are wanted.
Waveguides, gaskets and sealing elements requiring precise dimensions and good conductivity.
Gilding and plating base stock, and certain coinage and medal applications.
FAQ
Q: What is H96 copper alloy?
H96 is a copper-zinc brass with approximately 96 percent copper and zinc as the balance. It is a single-phase alpha brass with high ductility and conductivity and relatively low strength.
Q: Is H96 a high-strength brass?
No. High-strength brasses are multi-component alloys with additions such as aluminium, iron or manganese that raise strength. H96 has the lowest strength among the common brasses and is selected for conductivity and formability instead.
Q: What is the UNS equivalent of H96?
The closest equivalent is C21000, the gilding brass composition at about 95 percent copper. The European designation for the same family is CuZn5 or CuZn4.
Q: Can H96 copper alloy be strengthened by heat treatment?
No. It contains no second phase that responds to thermal treatment. Strength is controlled by cold reduction and by the choice of temper.
Q: What are the main uses of H96 copper alloy?
Its main uses are electrical and electronic components, heat transfer strip, deep-drawn and stamped parts, decorative metalwork and waveguide or sealing components.
Q: How does H96 differ from H62 brass?
H96 contains about 96 percent copper and offers much higher ductility and conductivity with lower strength, while H62 contains about 62 percent copper and provides substantially higher strength with lower conductivity and ductility.
