What Does Full-Hard (H04) Mean?
In the world of copper and copper alloys, temper designations describe the mechanical condition of the material. The H04 designation comes from the standard temper nomenclature used for copper alloys. It indicates that the material has been cold worked to a specific degree to achieve its final mechanical properties.
For C12200 copper, the temper progression generally looks like this:
O60 (Annealed): Softest condition. Maximum ductility, minimum strength.
H80 (Half-Hard or Drawn): Moderate cold work. Standard hard temper tube falls into this category.
H04 (Full-Hard): Significant cold work. Highest strength, lowest ductility.
Full-hard C12200 is produced by drawing the copper tube through a die after annealing. The cold working process introduces dislocations in the metal's crystal structure, which increases strength and hardness but reduces ductility. The more cold work applied, the harder and stronger the material becomes-and the less it will bend before cracking.
H04 represents a specific range of cold work, typically around 50 to 70 percent reduction in cross-sectional area from the annealed condition. The exact mechanical properties are defined in the applicable ASTM specifications.
How Does H04 Compare to Other Tempers?
The differences between tempers come down to mechanical properties. For C12200 copper, the tensile strength, yield strength, and elongation vary significantly depending on the temper.
| Temper | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation (%) | Typical Applications |
|---|---|---|---|---|
| O60 (Annealed) | 32 – 38 | 10 – 15 | 40 – 55 | Coiled tube, bending applications |
| H80 (Drawn) | 42 – 52 | 36 – 45 | 10 – 20 | Standard hard temper tube, straight lengths |
| H04 (Full-Hard) | 52 – 62 | 48 – 55 | 5 – 10 | High-strength components, spring applications |
What Specifications Cover Full-Hard C12200?
ASTM B75 – Seamless Copper Tube
ASTM B75 allows for H04 temper tube. When ordering, you specify the temper as "full-hard" or "H04" in addition to the alloy and specification. Not all suppliers stock H04 tube as a standard item, but it can be produced to order.
ASTM B152 – Copper Sheet, Strip, Plate, and Rolled Bar
If your application involves flat products rather than tube, ASTM B152 covers C12200 in H04 temper. This is common for components like bus bars, spring clips, and formed parts that require high strength.
ASTM B194 – Copper-Beryllium Alloy Plate, Sheet, Strip, and Rolled Bar
This one is worth mentioning because full-hard copper is sometimes confused with copper-beryllium alloys. They are not the same. Copper-beryllium can be heat treated to even higher strengths, but full-hard C12200 offers a good balance of strength, conductivity, and corrosion resistance without the added cost and handling considerations of beryllium alloys.
For tube applications, ASTM B75 is the primary specification to reference when sourcing H04 C12200.
What Are the Mechanical Properties of Full-Hard C12200?
| Property | Typical Value (H04 Temper) |
|---|---|
| Tensile Strength | 55 – 62 ksi (379 – 427 MPa) |
| Yield Strength (0.2% offset) | 48 – 55 ksi (331 – 379 MPa) |
| Elongation (in 2 inches) | 5 – 10% |
| Hardness (Rockwell F) | 95 – 105 |
| Modulus of Elasticity | 17,000 ksi (117 GPa) |
| Property | Value |
|---|---|
| Thermal Conductivity | 196 BTU/ft·hr·°F (339 W/m·K) |
| Electrical Conductivity | 85% IACS |
| Corrosion Resistance | Excellent in most environments |
What Applications Use Full-Hard C12200?
Spring Contacts and Electrical Components
In electrical equipment, full-hard copper is used for spring contacts, connector components, and current-carrying parts that need to maintain contact pressure over time. The combination of high strength and good electrical conductivity makes H04 C12200 a practical choice for these applications.
Mechanical Components
Any mechanical component that needs to hold its shape under load-clips, retainers, fasteners, structural elements-can benefit from the strength of full-hard copper. It is often used in assemblies where the copper part must resist deformation from mating components or environmental stresses.
Bus Bars and Conductors
While soft copper is more common for bus bars that are formed after installation, full-hard C12200 is used when the bus bar needs to maintain a precise shape without additional support. The higher strength allows for longer spans between supports or thinner sections for the same current-carrying capacity.
Heat Exchanger Components
In some heat exchanger designs, full-hard copper tube is used for components that must resist mechanical stress from vibration, pressure cycling, or thermal expansion. The higher yield strength provides an extra margin of safety in demanding operating conditions.
Custom Fabrication
When fabricating complex assemblies that require copper components to mate with other materials under preload, full-hard temper provides the rigidity needed to maintain tolerances during assembly and service.
Discuss Your Project Requirements
FAQ
What is the difference between H80 and H04?
H80 (standard hard temper) is cold worked to a moderate degree, typically with yield strengths in the 36 to 45 ksi range. H04 (full-hard) receives significantly more cold work, with yield strengths typically above 48 ksi. H04 is about 30 to 40 percent stronger than H80, but with much lower ductility.
Can I bend full-hard C12200?
Generally, no. Full-hard copper has very limited ductility and will crack if bent. If you need a copper component with bends, start with annealed material, form it to shape, and then either leave it in the annealed condition or work-harden it through cold work after forming.
Is full-hard C12200 suitable for welding?
Yes, but with caution. The heat from welding will anneal the material in the heat-affected zone, reducing strength locally. For structural applications, this may or may not be acceptable. Brazing or soldering are often better choices for joining full-hard components because they involve less heat input.
What is the typical lead time for H04 C12200 tube?
Full-hard tube is less common than annealed or standard hard temper, so it may not be stocked in large quantities. Lead times vary depending on the size, wall thickness, and quantity. It is always worth confirming availability with your supplier before placing an order.
Does full-hard C12200 cost more than standard hard temper?
Pricing depends on the specific product form and quantity. Because H04 is a specialty temper, it may carry a premium over standard hard temper tube. However, for applications that require the higher strength, the added cost is often justified by improved performance or the ability to use thinner sections.
Our product range
| Product Category | Key Specifications | Common Applications |
|---|---|---|
| Copper Tubes | Outer Diameter: 3–300 mm Wall Thickness: 0.5–10 mm Length: Customized Standards: ASTM B280, EN 1057, JIS H3300 |
Air conditioning, refrigeration, heat exchangers, plumbing, industrial fluid transfer |
| Copper Sheets & Plates | Thickness: 0.5–100 mm Width: up to 3000 mm Length: up to 6000 mm Standards: ASTM B152, EN 1652, GB/T 2040 |
Architectural roofing, busbars, transformer components, industrial panels, heat exchangers |
| Copper Rods & Bars | Diameter: 6–300 mm (round) Cross-section: square, hexagonal, flat Standards: ASTM B124, EN 12163, GB/T 4423 |
Electrical connectors, machining parts, switchgear, fasteners, valve stems |
| Copper Wires | Diameter: 0.1–12 mm Form: bare, tinned, stranded Standards: ASTM B3, EN 13601, IEC 60228 |
Electrical wiring, cables, grounding, automotive harnesses, transformer windings |
Our factory
Our factory is equipped with a comprehensive range of advanced production facilities dedicated to the copper processing industry. The production line includes state-of-the-art extrusion presses, precision rolling mills, high-speed drawing machines, continuous casting lines, and automated annealing furnaces, enabling us to manufacture a full spectrum of copper products-tubes, sheets, plates, rods, bars, wires, and strips-with exceptional dimensional accuracy and consistent mechanical properties. To ensure stable output and supply reliability, we operate with an annual production capacity exceeding 80000 tons and maintain a large-scale inventory system that supports just-in-time delivery. Complementing our manufacturing capabilities is a dedicated quality control center equipped with spectrometers, universal testing machines, and hardness testers, ensuring every batch meets international standards such as ASTM, EN, and GB/T. This vertically integrated production setup allows us to control quality at every stage, from raw material selection to final packaging, and to offer flexible customization in dimensions, temper, and surface finishes. With decades of technical expertise and a strong focus on continuous process improvement, we stand as a reliable, large-scale supplier serving clients across global markets.
Check Today's Stock & Lead Time
