Two Ends of the Ordinary Brass Range
H96 and H62 are the two most widely specified ordinary binary copper-zinc brasses in the GB/T 5231 designation system, commonly supplied as plate, strip, sheet, rod, tube and wire under the corresponding product-form standards. They are not simply two strength levels of the same material: they sit at opposite ends of the copper-zinc range and their structures are different, which is why they behave differently in every respect from conductivity to hot working response.
H96 contains 95.0 to 97.0 percent copper with the balance zinc, only about three to five percent. The result is a single-phase alpha alloy whose mechanical, electrical and thermal properties sit close to those of pure copper, which makes it the natural choice where a near-copper material with slightly better strength and lower cost is acceptable. H62 contains 60.5 to 63.5 percent copper with approximately 36.5 to 39.5 percent zinc, and at that composition the alloy is a two-phase alpha plus beta duplex brass. That duplex structure delivers markedly higher strength, better machinability and an excellent hot working response.
Chemical Composition Under GB/T 5231
| Element | H96 | H62 |
|---|---|---|
| Copper (Cu), % | 95.0 to 97.0 | 60.5 to 63.5 |
| Zinc (Zn), % | Balance, about 3 to 5 | Balance, about 36.5 to 39.5 |
| Iron (Fe), % max | 0.10 | 0.15 |
| Lead (Pb), % max | 0.03 | 0.08 |
| Other impurities, % max | 0.2 | 0.5 |
| Alloy type | Single-phase alpha brass | Duplex alpha plus beta brass |
Approximate International Equivalents
| GB grade | UNS, USA | EN, Europe | JIS, Japan |
|---|---|---|---|
| H96 | C21000, approximate | CW500L / CuZn5, approximate | C2100, approximate |
| H62 | C27400 / C28000, approximate | CW508L / CuZn37, approximate | C2800 / C2720, approximate |
These equivalents are approximate and not interchangeable. The copper ranges overlap but are not identical, and the product-form standards differ between systems, so substituting one designation for another requires engineering review of composition, temper and the applicable product standard.
Mechanical Properties by Temper
| Temper | H96, typical | H62, sheet and plate |
|---|---|---|
| Soft, O60 | Tensile about 205 MPa or more; elongation about 35% | Tensile 290 MPa or more; elongation 35% or more; HV 95 max |
| Half hard, H02 | Tensile about 245 to 345 MPa | Tensile 350 to 470 MPa; elongation 20% or more; HV 90 to 130 |
| Hard, H04 | Tensile about 320 to 345 MPa | Tensile 410 to 630 MPa; elongation 10% or more; HV 125 to 165 |
| Extra hard, H06 | Not normally supplied | Tensile 585 MPa or more; elongation 2.5% or more; HV 155 or more |
The pattern is clear. H62 spans a much wider strength range and reaches levels H96 cannot approach, while H96 gains very little from cold reduction and loses ductility while doing so. For any application needing temper-dependent strength, H62 is the appropriate grade; for applications needing maximum ductility and conductivity, H96 is.
Physical Properties and Processing Behaviour
| Property | H96 | H62 |
|---|---|---|
| Density | 8.85 g/cm³ | 8.43 g/cm³ |
| Electrical conductivity | About 56% IACS | About 27 to 28% IACS |
| Thermal conductivity | About 230 to 240 W/(m·K) | About 110 to 120 W/(m·K) |
| Melting range | About 1050 to 1075 degrees Celsius | About 899 to 906 degrees Celsius |
| Colour | Reddish, close to copper | Bright golden-yellow |
| Cold working | Excellent: deep drawing, bending, spinning in soft temper | Good, but multi-stage forming needs intermediate annealing |
| Hot working | Good, about 775 to 850 degrees Celsius | Excellent, about 700 to 750 degrees Celsius |
Hot working behaviour is the sharpest practical difference. The beta phase in H62 makes it flow readily under hot deformation, which is why forged and extruded fittings are overwhelmingly made from duplex brasses. H96 must be hot worked at a higher temperature and offers less margin for error. Conversely, H96 in the soft condition is one of the most formable copper alloys available for cold work, being suited to deep drawing, severe bending and spinning, while H62 work hardens faster and needs an annealing step between forming stages.
Selection Guide
Choose H96 when: conductivity or thermal conductivity is a governing requirement; a near-copper colour and patina are wanted for exposed architectural work; deep drawing, spinning or severe bending of thin strip is required; or fresh-water and atmospheric corrosion resistance with no stress corrosion cracking risk is needed.
Choose H62 when: strength, hardness or spring characteristics are specified; hot forging or extrusion is the manufacturing route; machinability matters; a bright yellow decorative colour is acceptable; or the lowest material cost for a given strength is the deciding factor.
Confirm before substituting: the composition window of the equivalent designation, the required temper, and the product-form standard that governs dimensions and tolerances.
FAQ
Q: What is the fundamental difference between H96 and H62 brass?
Copper content and structure. H96 has 95 to 97 percent copper and is a single-phase alpha alloy close to pure copper, while H62 has 60.5 to 63.5 percent copper and is a duplex alpha plus beta alloy with much higher strength.
Q: Which grade is more conductive?
H96, at about 56 percent IACS, against about 27 to 28 percent IACS for H62.
Q: Which grade is stronger?
H62. In hard temper, sheet and plate reach 410 to 630 MPa, whereas H96 tops out around 320 to 345 MPa and loses ductility in the process.
Q: Which grade hot works more easily?
H62. Its beta phase gives it excellent hot deformability at about 700 to 750 degrees Celsius, which is why forged and extruded fittings usually use it.
Q: Are H96 and C21000 the same material?
They are approximate equivalents, not identical. The copper ranges overlap but differ, and the product-form standards are not interchangeable without engineering review.
Q: How do the two grades compare in colour?
H96 has a reddish colour close to copper, while H62 is a bright golden-yellow. For decorative work this difference can be the deciding factor.
