Designation and Standards
H96 is a low-zinc ordinary brass, nominally 96 percent copper with zinc as the balance, and it belongs to the Cu-Zn family with a copper content of 95 to 97 percent. Its grade designation and chemical composition are governed by GB/T 5231, while the product-form requirements for strip, plate, tube and rod are covered by the corresponding national product standards, including GB/T 2059 for strip and GB/T 1527 for tube. In American practice the closest designation is UNS C21000 and in European practice CW500L, although the composition windows overlap rather than coincide exactly.
H96 is supplied as coil and strip in thicknesses from about 0.1 mm to 3.0 mm, and as companion forms in bar, plate, tube and wire. Its commercial appeal is straightforward: it behaves very much like pure copper in conductivity, corrosion resistance and colour, but offers higher strength and a lower cost than unalloyed copper.
Chemical Composition
| Element | Content, % |
|---|---|
| Copper (Cu) | 95.0 to 97.0 |
| Zinc (Zn) | Balance |
| Iron (Fe) | 0.10 max |
| Lead (Pb) | 0.03 max |
| Nickel (Ni) | 0.5 max |
| Total other impurities | 0.2 max |
With only about three to five percent zinc, H96 remains a single-phase alpha solid solution. That structure explains its characteristic behaviour: high conductivity, excellent cold formability and a soft reddish-golden colour that is visibly different from the bright yellow of H62 or H65.
Physical Properties
| Property | Typical value | Basis |
|---|---|---|
| Density | 8.85 g/cm³ | Room temperature |
| Electrical conductivity | About 56% IACS | Low-zinc brass near the CuZn5 composition |
| Thermal conductivity | About 230 W/(m·K) | Room temperature |
| Melting range | About 1050 to 1075 degrees Celsius | Alloy melting range |
| Coefficient of thermal expansion | About 18.5 × 10-6 per degree Celsius | 20 to 300 degrees Celsius |
Conductivity is the reason most buyers specify H96. At roughly 56 percent IACS it sits well above the ordinary brasses such as H62 at about 27 percent, but below oxygen-free and tough pitch coppers. Where a project needs maximum conductivity, unalloyed copper remains the answer; where a moderate reduction in conductivity is acceptable in exchange for higher strength, better hot formability and lower cost, H96 is the efficient choice.
Mechanical Properties and Tempers
| Property | Value | Condition |
|---|---|---|
| Tensile strength | 205 to 320 MPa | Temper dependent |
| Elongation | 3 to 45% | Up to about 45% in soft temper |
| Hardness | About 45 to 105 HV | Tube and strip, temper dependent |
| Annealing temperature | 540 to 600 degrees Celsius | For stress relief and softening |
| Hot working range | 640 to 850 degrees Celsius | Recommended range |
Soft tempers are the norm for coil and strip destined for deep drawing, spinning and severe bending, and hard tempers are used where stiffness and spring characteristics are required. Because H96 is the weakest of the common brasses, a design that needs high yield strength should move to a lower-copper grade rather than specify a harder temper of H96, which rapidly loses ductility.
Applications and Selection Notes
Electronics and electrical: conductive terminals, heat sinks and relay components, where the balance of conductivity, formability and cost is decisive.
Architectural decoration: door handles, plumbing fittings and decorative mouldings, where the warm colour and tarnish behaviour of a high-copper brass are assets.
Shipbuilding and automotive: freshwater-resistant piping joints and instrument parts, subject to the caveat below.
Industrial manufacturing: cold-headed parts, rivets and welded structural components.
Heat exchangers and waveguide tubing: thermal duty in low-chloride service and, in strip form, formed waveguide components.
One caveat matters commercially: H96 has no tendency to stress corrosion cracking in normal service and performs well in fresh water and in the atmosphere, but it is not a seawater alloy. If chlorides are present, tin-bearing brass, aluminium bronze or a cupronickel is required. A second caveat concerns corrosion product colour: high-copper brasses form a reddish-brown patina rather than the blue-green of higher-zinc alloys, which may or may not be acceptable for exposed architectural work.
FAQ
Q: What is the difference between H96 and red copper?
H96 is a copper-zinc alloy containing 95 to 97 percent copper, so it is stronger than unalloyed copper but slightly less conductive. Red copper is 99.9 percent copper or higher, with the best conductivity and the lowest strength.
Q: What is the colour of H96 brass?
It has a light reddish-golden colour due to the high copper content, clearly different from the bright yellow of H62 and distinctly different from the reddish-purple of red copper.
Q: What thicknesses are available in H96 coil and strip?
Common commercial coverage runs from about 0.1 mm to 3.0 mm, with precision strip produced in narrower and thinner ranges to order.
Q: Is H96 brass suitable for seawater environments?
No. H96 is recommended for atmospheric and freshwater service. Seawater duty requires a tin-bearing brass, an aluminium bronze or a cupronickel.
Q: What is the electrical conductivity of H96 brass?
Approximately 56 percent IACS, well above the ordinary brasses but below unalloyed copper. Thermal conductivity is correspondingly high, at around 230 W/(m·K).
Q: How is H96 strip annealed?
Typically between 540 and 600 degrees Celsius to relieve internal stress and restore ductility between forming operations.
Q: Which temper should be ordered for deep drawing?
Soft temper. H96 in the soft condition supports deep drawing, severe bending and spinning, while hard tempers are intended for stiffness and spring duty.
