What Do the H62 and H65 Designations Mean
H62 and H65 are brass grade designations under the Chinese system governed by GB/T 5231 for wrought copper and copper alloy products. The number after H indicates the nominal copper percentage. H62 brass contains 60.5 to 63.5 percent copper, and H65 contains 63.5 to 68.0 percent copper, with zinc as the balance in both cases. In the UNS system, H62 corresponds to C28000 (60/40 Muntz-type brass) and H65 to C26800 or C27000, depending on the exact copper range.
Composition and Property Differences
| Property | H62 Brass Pipe | H65 Brass Pipe |
|---|---|---|
| Copper content | 60.5 - 63.5% | 63.5 - 68.0% |
| Zinc content | Higher | Lower |
| Strength and hardness | Higher | Slightly lower |
| Plasticity and formability | Good | Better, especially for bending and deep drawing |
| Corrosion resistance | Adequate for general service | Better in humid and mildly acidic environments |
| Thermal and electrical conductivity | Moderate | Slightly higher |
| Cost | Lower | Higher due to copper content |
Typical Applications of H62 Brass Pipe
H62 is specified where strength matters more than appearance or corrosion margin: mechanical structures, valve stems and fittings, bearing bushings, radiator tubes and general water supply and HVAC pipe in normal environments. Its lower copper content keeps the material economical for projects with tight budgets and no severe service exposure.
Typical Applications of H65 Brass Pipe
H65 is chosen for complex forming operations and for service where corrosion resistance is a deciding factor. Typical uses include deep-drawn and bent components, musical instrument tubing, decorative and architectural tube, condenser and heat exchanger tube in moderately aggressive water, and fittings that must survive humid or mildly acidic environments. The higher copper content also gives slightly better conductivity for heat-transfer duty.
Selection Guidance
Select H62 when the part is load-bearing, the environment is benign, and cost is a primary constraint. Select H65 when the part must be bent or drawn to a tight radius, when the water chemistry is aggressive, or when thermal and electrical conductivity contribute to system performance. Where doubt exists, H65 provides a wider safety margin at a modest cost premium.
Frequently Asked Questions
Q: What is the copper content of H62 brass pipe?
A: 60.5 to 63.5 percent, per GB/T 5231.
Q: Is H62 the same as C28000?
A: Yes, the UNS equivalent of H62 is C28000, a 60/40 brass.
Q: Which grade is stronger, H62 or H65?
A: H62, because its higher zinc content provides greater strength and hardness.
Q: Which grade bends better?
A: H65, whose higher copper content gives superior plasticity for bending, flaring and deep drawing.
Q: Is H65 worth the price premium?
A: For corrosive or humid service and complex forming, yes; for simple structural and plumbing duty, H62 is usually sufficient.
Q: Do H62 and H65 meet international standards?
A: Both grades have UNS and EN equivalents, so they are routinely supplied to ASTM B135 or EN 12449 when the project requires them.
