Introduction
This article explains C21000 and H96 brass, covering composition, properties and uses. Chinese brass grades such as H96, H90, H68, H65, H62 and H59 are defined in GB/T 5231 by their copper content and are the standard designations used in the Chinese copper industry. The number after H gives the nominal copper percentage, so H62 contains about 62 percent copper and H96 about 96 percent.
Grade System
In the Chinese system, H96 and H90 are high-copper brasses with excellent formability and conductivity, H68 and H65 are single-phase brasses with the best cold-forming behavior, H62 is the general-purpose grade balancing strength, cost and formability, and H59 is a two-phase brass with the lowest copper content and the highest strength at lower cost. The same products are designated by UNS numbers in ASTM practice, with H96 corresponding to C21000 and H62 corresponding approximately to C27400.
Properties by Grade
Higher copper content gives better ductility, corrosion resistance and conductivity, while higher zinc gives more strength and lower cost. For deep drawing, H68 and H65 are preferred because of their excellent elongation; for general hardware, fasteners and fittings, H62 offers the best balance; for hot working and economical parts, H59 is used.
| Grade | Cu % | Character | Typical Use |
|---|---|---|---|
| H96 | 95 - 97 | High ductility | Radiator tubes, fine products |
| H68 | 67 - 70 | Best deep drawing | Shells, hardware |
| H65 | 63.5 - 66.5 | Good formability | Fasteners, terminals |
| H62 | 60.5 - 63.5 | General purpose | Fittings, wire, tube |
| H59 | 57 - 60 | Two-phase, strong | Hot-worked parts |
Applications
Chinese brass grades are used for radiator tubes, fasteners, terminals, hardware, deep-drawn shells, instruments, condenser tubes and decorative products. Each grade is supplied as sheet, strip, rod, wire and tube according to the product standard such as GB/T 2040 for sheet and strip, GB/T 1527 for drawn tube and GB/T 4423 for rod.
Selection and Verification
Confirm the copper content range against GB/T 5231 and the product form against the relevant product standard. Verify the mechanical properties and the chemical analysis on the certificate, and match the grade to the forming and corrosion requirements of the part.
