Overview
H70 Brass is a high-copper alpha brass alloy containing approximately 69–71% copper and the balance zinc. It is equivalent to C26000 (Cartridge Brass) and CuZn30 under international standards. H70 is renowned for its outstanding ductility, formability, corrosion resistance, electrical conductivity, thermal conductivity, and aesthetic appearance.
Among common H-series brass grades, H70 has one of the highest copper contents, providing exceptional cold-working performance and deep-drawing capability. It is widely used in precision stamping, cartridge cases, electrical components, decorative hardware, and heat transfer applications.
H70 brass is widely used in:
- Cartridge Cases
- Electrical Connectors
- Heat Exchanger Components
- Radiator Parts
- Decorative Hardware
- Precision Stampings
- Deep Drawn Components
- Musical Instruments
Its superior formability makes H70 one of the most popular brass grades for complex formed products.
Material Specification
| Property | Value |
|---|---|
| Material Designation | H70 Brass |
| Chinese Standard | GB/T 5231 |
| Material Family | Copper-Zinc Brass Alloy |
| Density | 8.53 g/cm³ |
| Magnetic Property | Non-Magnetic |
| Typical Supply Condition | Annealed, Half-Hard, Hard |
| Standard Forms | Sheet, Strip, Plate, Rod, Tube |
Chemical Composition
| Element | Content (%) |
|---|---|
| Copper (Cu) | 69.0–71.0 |
| Zinc (Zn) | Balance |
| Lead (Pb) | ≤0.03 |
| Iron (Fe) | ≤0.10 |
| Impurities | ≤0.30 |
The high copper content provides excellent ductility, corrosion resistance, and conductivity.
Mechanical Properties
Annealed Condition
| Property | Value |
|---|---|
| Tensile Strength | 280–380 MPa |
| Yield Strength | 70–150 MPa |
| Elongation | 50–70% |
| Hardness | 50–85 HB |
| Elastic Modulus | 105 GPa |
Cold Worked Condition
| Property | Value |
|---|---|
| Tensile Strength | 420–620 MPa |
| Yield Strength | 220–480 MPa |
| Hardness | 110–180 HB |
Physical Properties
| Property | Value |
|---|---|
| Density | 8.53 g/cm³ |
| Melting Point | 915–950°C |
| Thermal Conductivity | 120 W/m·K |
| Electrical Conductivity | 28–30% IACS |
| Electrical Resistivity | 0.061 μΩ·m |
| Thermal Expansion Coefficient | 20.5 × 10⁻⁶/K |
| Specific Heat Capacity | 380 J/kg·K |
Electrical Conductivity
| Material | Conductivity (% IACS) |
|---|---|
| C110 Copper | 100 |
| H70 Brass | 28–30 |
| H68 Brass | 27–28 |
| H65 Brass | 26–27 |
| H62 Brass | 25–28 |
H70 offers the highest conductivity among common H-series brass grades.
Thermal Conductivity
| Material | Thermal Conductivity (W/m·K) |
|---|---|
| C110 Copper | 390 |
| H70 Brass | 120 |
| H68 Brass | 116 |
| H65 Brass | 114 |
| Stainless Steel 304 | 16 |
The excellent thermal conductivity makes H70 suitable for heat exchangers and cooling systems.
Corrosion Resistance
| Environment | Performance |
|---|---|
| Indoor Environment | Excellent |
| Dry Atmosphere | Excellent |
| Fresh Water | Excellent |
| Marine Atmosphere | Good |
| Salt Water | Moderate |
| Industrial Environment | Excellent |
The high copper content provides excellent resistance to atmospheric and industrial corrosion.
Recommended surface treatments:
- Nickel Plating
- Chrome Plating
- Gold Plating
- Tin Plating
- Electropolishing
- Clear Protective Coating
Weldability
| Welding Process | Rating |
|---|---|
| TIG Welding | Good |
| MIG Welding | Good |
| Resistance Welding | Excellent |
| Brazing | Outstanding |
| Soldering | Outstanding |
H70 is commonly fabricated using brazing and soldering processes.
Machinability
| Process | Rating |
|---|---|
| CNC Turning | Good |
| CNC Milling | Good |
| Drilling | Good |
| Grinding | Good |
| Stamping | Outstanding |
| Deep Drawing | Outstanding |
Machinability Comparison
| Material | Machinability |
|---|---|
| C360 Brass | Excellent |
| H59 Brass | Excellent |
| H70 Brass | Good |
| H68 Brass | Good |
| C110 Copper | Fair |
H70 is selected primarily for forming and deep-drawing operations rather than high-speed machining.
Heat Treatment
Stress Relief Annealing
| Parameter | Value |
|---|---|
| Temperature | 250–350°C |
| Cooling Method | Air Cool |
Full Annealing
| Parameter | Value |
|---|---|
| Temperature | 500–650°C |
| Cooling Method | Air Cool |
Heat Treatability
| Property | Performance |
|---|---|
| Hardening by Heat Treatment | No |
| Cold Work Strengthening | Yes |
| Annealing Response | Excellent |
H70 gains strength through cold working and strain hardening.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| GB/T (China) | H70 |
| ASTM (USA) | C26000 |
| UNS | C26000 |
| EN (Europe) | CuZn30 |
| DIN (Germany) | CW505L |
| JIS (Japan) | C2600 |
| ISO | CuZn30 |
Available Forms
| Product Type | Availability |
|---|---|
| Sheet | Yes |
| Strip | Yes |
| Plate | Yes |
| Round Bar | Yes |
| Flat Bar | Yes |
| Tube | Yes |
| Wire | Yes |
Typical Applications
Electrical Industry
- Electrical Connectors
- Terminals
- Contact Components
- Conductive Hardware
Ammunition Industry
- Cartridge Cases
- Shell Components
- Precision Drawn Parts
HVAC Industry
- Heat Exchanger Components
- Radiator Parts
- Condenser Components
- Cooling System Hardware
Architectural Industry
- Decorative Trim
- Nameplates
- Door Hardware
- Decorative Panels
Musical Instrument Industry
- Trumpets
- Trombones
- Horn Components
Industrial Manufacturing
- Precision Stampings
- Deep Drawn Components
- Brass Fabrications
- Formed Parts
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| CNC Machining | Good |
| Stamping | Outstanding |
| Deep Drawing | Outstanding |
| Welding | Good |
| Brazing | Outstanding |
| Soldering | Outstanding |
| Electroplating | Excellent |
Advantages
Outstanding Formability
Excellent for deep drawing, spinning, bending, and precision stamping.
Excellent Corrosion Resistance
Higher copper content improves durability in industrial environments.
High Conductivity
One of the highest conductivity levels among commercial brass alloys.
Attractive Appearance
Bright golden color ideal for decorative applications.
Excellent Fabrication Performance
Supports forming, brazing, soldering, and plating.
Wide Industrial Use
Suitable for electrical, HVAC, decorative, and precision manufacturing applications.
Limitations
Lower Strength Than H59
Not recommended for heavily loaded structural applications.
Lower Conductivity Than Pure Copper
Cannot replace copper in high-current electrical systems.
Moderate Wear Resistance
Not ideal for severe abrasion conditions.
Marine Applications May Require Protection
Additional coatings may be necessary in aggressive seawater environments.
Comparison with Other Brass Grades
| Property | H70 | H68 | H65 | H62 | H59 |
|---|---|---|---|---|---|
| Copper Content | 69–71% | 67–70% | 63–68% | 60.5–63.5% | 57–60% |
| Formability | Outstanding | Outstanding | Excellent | Excellent | Good |
| Corrosion Resistance | Best | Excellent | Excellent | Good | Good |
| Conductivity | Highest | High | Good | Good | Lower |
| Strength | Moderate | Moderate | Moderate | High | Highest |
Comparison with Common Materials
| Material | Conductivity | Strength | Formability |
|---|---|---|---|
| H70 Brass | 28–30% IACS | Moderate | Outstanding |
| H68 Brass | 27–28% IACS | Moderate | Outstanding |
| H62 Brass | 25–28% IACS | High | Excellent |
| C110 Copper | 100% IACS | Lower | Excellent |
| Stainless Steel 304 | 2% IACS | High | Good |
Available Surface Finishes
Raw Finishes
- Mill Finish
- Bright Finish
- Annealed Finish
Functional Finishes
- Precision Machined Finish
- Brushed Finish
- Polished Finish
Decorative Finishes
- Nickel Plated
- Chrome Plated
- Gold Plated
- Tin Plated
Frequently Asked Questions (FAQ)
What is H70 brass?
H70 is a high-copper brass alloy containing approximately 69–71% copper, known for excellent formability and corrosion resistance.
What is H70 brass used for?
Typical applications include:
- Cartridge Cases
- Electrical Connectors
- Heat Exchangers
- Decorative Hardware
- Deep Drawn Components
What is the equivalent material to H70?
Common equivalents include:
- C26000
- CuZn30
- CW505L
- C2600
What is the difference between H70 and H68?
| Property | H70 | H68 |
|---|---|---|
| Copper Content | Higher | Slightly Lower |
| Conductivity | Higher | High |
| Formability | Similar | Similar |
| Corrosion Resistance | Slightly Better | Excellent |
Is H70 suitable for deep drawing?
Yes. H70 is one of the best brass grades for deep drawing and cartridge manufacturing.
Can H70 be machined?
Yes. H70 provides good machinability but is primarily selected for forming operations.
Is H70 corrosion resistant?
Yes. H70 offers excellent atmospheric and industrial corrosion resistance.
Why choose H70 brass?
Because it combines:
- Outstanding Formability
- Excellent Corrosion Resistance
- High Conductivity
- Attractive Appearance
- Excellent Fabrication Characteristics
Is H70 suitable for cartridge cases?
Yes. H70 is internationally known as Cartridge Brass and is widely used for ammunition cases.
Does GCNOV provide custom manufacturing services for H70 brass?
Yes. GCNOV provides:
- CNC Machining
- Precision Stamping
- Deep Drawing
- Brass Fabrication
- Surface Plating
- Prototype Development
- Low-Volume Production
- Mass Production