Copper Pressing and Stamping

A Comprehensive Guide to Materials, Processes, Equipment, and Applications

Copper pressing and stamping are manufacturing processes that transform copper sheet metal into specific shapes and components through mechanical deformation. These processes are fundamental to numerous industries, including electronics, automotive, construction, and consumer products manufacturing.

Dating back thousands of years, copper was among the first metals to be worked by humans. Modern pressing and stamping techniques have evolved significantly from these ancient beginnings, incorporating advanced technologies, precision machinery, and sophisticated material science to produce components with incredible accuracy and performance characteristics.

Key Advantages of Copper in Pressing and Stamping:

• Excellent electrical conductivity – second only to silver among common metals
• Superior thermal conductivity – efficiently transfers and dissipates heat
• High ductility and malleability – easily formed without fracturing
• Good corrosion resistance – forms a protective patina
• Antimicrobial properties – naturally inhibits bacterial growth
• Recyclability – can be recycled repeatedly without degradation
• Aesthetic appeal – distinctive color and finish options

Common Industries and Applications:

• Electronics – connectors, terminals, busbars, heat sinks
• Automotive – radiators, brake systems, electrical components
• Construction – roofing, flashing, decorative elements
• Plumbing – fittings, valves, pipe components
• Renewable Energy – solar panel components, wind turbine parts
• Telecommunications – antennas, connection hardware
• Consumer Goods – cookware, hardware, decorative items

Copper Materials and Grades

The selection of the appropriate copper material is crucial for achieving the desired mechanical, electrical, thermal, and corrosion-resistant properties in pressed and stamped components. Copper and its alloys are classified according to standardized designation systems, with each grade offering specific characteristics suited to particular applications.

Pure Copper Grades

Copper Alloy Grades

Material Selection Factors

Technical Considerations:

• Mechanical properties – strength, hardness, ductility
• Electrical conductivity – IACS % rating (International Annealed Copper Standard)
• Thermal conductivity – W/mK rating
• Corrosion resistance – environmental exposure conditions
• Formability – ability to be shaped without cracking
• Springback characteristics – especially important for precision parts
• Work hardening rate – changes in hardness during forming
• Grain structure – affects mechanical properties and surface finish

Practical Considerations:

• Cost – material price and production economics
• Material availability – standard stock sizes and lead times
• Secondary operations – plating, cleaning, joining requirements
• Regulatory compliance – RoHS, REACH, and other standards
• Recyclability – end-of-life considerations
• Industry standards – ASTM, ISO, EN specifications
• Surface finish requirements – aesthetic and functional needs
• Machinability – if secondary machining is required

Material Temper Designations

Copper materials are available in various tempers that define their metallurgical state and mechanical properties. The temper significantly impacts formability and spring characteristics:

Copper Pressing and Stamping Processes

Copper pressing and stamping encompass a range of metal forming processes that shape copper sheet metal into functional components. These processes vary based on complexity, production volume, and the specific characteristics of the desired parts.

Blanking

Blanking Process Illustration

A cutting operation where a flat shape (blank) is cut from a larger sheet of copper. The cut piece becomes the workpiece for further operations.

Key characteristics: Clean cut edges, dimensionally accurate blanks, minimal material distortion.

Applications: Electrical terminals, washers, brackets, first step in progressive die stamping.

Piercing/Punching

Piercing Process Illustration

Creating holes or openings in the copper sheet by pushing a punch through the material and into a die.

Key characteristics: Ability to create various hole shapes and patterns, controlled burr formation.

Applications: Ventilation holes, mounting holes, perforated sheets, connector features.

Bending

Bending Process Illustration

Deforming the copper sheet along a straight axis to create angles, channels, or other profile shapes.

Key characteristics: Requires accounting for springback, bend radius control important for crack prevention.

Applications: Brackets, clips, flanges, enclosures, structural components.

Deep Drawing

Deep Drawing Process Illustration

Forming a sheet metal blank into a hollow shape by pulling it into a die cavity using a punch.

Key characteristics: Capable of creating complex 3D shapes, may require multiple drawing operations for deep parts.

Applications: Cups, cans, shells, enclosures, housings for electronic components.

Coining

Coining Process Illustration

A closed-die forging process where high pressure compresses the copper between two dies, causing plastic flow into die cavities.

Key characteristics: Creates precise details, requires high tonnage, minimal material flow.

Applications: Electrical contacts, coins, medallions, detailed embossed features.

Embossing

Embossing Process Illustration

Creating raised or recessed designs in the copper sheet by pressing it between matching male and female dies.

Key characteristics: Decorative or functional surface features, minimal material thickness change.

Applications: Heat sink fins, decorative panels, anti-slip surfaces, identification markings.

Progressive Die Stamping

Progressive die stamping is a highly efficient process for producing complex copper components in high volumes. The process uses a series of stations within a single die set, with each station performing a specific operation as the copper strip advances through the die.

Progressive Die Stamping Advantages:

• High production rates (typically 20-1,500 strokes per minute)
• Excellent part-to-part consistency
• Reduced handling between operations
• Multiple operations in a single press stroke
• Automation-friendly for high-volume production
• Cost-effective for large production runs

Progressive Die Stamping Limitations:

• High initial tooling costs
• Longer lead times for die design and fabrication
• Not economical for low-volume production
• Limited to certain part geometries
• Material utilization may not be optimal
• Complex die maintenance requirements

Fine Blanking

Fine blanking is a specialized pressing process that produces parts with extremely clean, straight-cut edges throughout the entire material thickness. This high-precision process is particularly valuable for copper components that require tight tolerances and excellent edge quality without secondary operations.

The process uses a triple-action press that applies pressure in three directions simultaneously:

1. The stinger (V-ring) impinges the material to prevent radial material flow
2. The pressure pad holds the material flat during blanking
3. The punch performs the blanking operation with minimal clearance

Applications: High-precision electrical connectors, relay components, complex flat parts requiring tight tolerances and excellent edge quality.

Forming Process Selection Factors

Equipment for Copper Pressing and Stamping

Press Types

Mechanical Presses

Mechanical presses use a motor-driven flywheel and crankshaft to convert rotational energy to linear force for stamping operations.

Key characteristics:

• Available in capacities from 20 to 4,000+ tons
• Stroke rates from 20 to 1,500 strokes per minute
• Maximum force occurs near bottom dead center
• Energy-efficient for high-volume production
• Types include: gap frame (C-frame), straight-side, knuckle-joint

Best for: High-volume production, progressive die operations, operations requiring consistent stroke length

Hydraulic Presses

Hydraulic presses use fluid pressure to generate force for pressing and stamping operations.

Key characteristics:

• Available in capacities from 20 to 10,000+ tons
• Full pressing force available throughout the stroke
• Adjustable stroke length and pressure
• Lower stroke rates than mechanical presses
• More energy consumption but greater flexibility

Best for: Deep drawing operations, jobs requiring dwell time at pressure, variable stroke requirements, heavier forming operations

Servo Presses

Modern press technology using servo motors to provide programmable slide motion and force control.

Key characteristics:

• Highly programmable motion profiles
• Energy efficiency (30-50% less than conventional presses)
• Precision control of position, velocity, and force
• Capacity range from 80 to 3,000+ tons
• Excellent repeatability and process control

Best for: Complex forming operations, precision components, difficult-to-form materials, operations requiring optimized motion profiles

Specialized Presses

Purpose-built presses designed for specific copper forming operations.

• Transfer Presses: Handle parts between multiple dies with automated transfer systems
• Fine Blanking Presses: Triple-action presses for high-precision blanking
• Coining Presses: High-tonnage presses with precise alignment for detailed impression work
• Hot Forming Presses: Equipped with heating elements for hot forming copper alloys
• Four-Post Presses: Provide exceptional parallelism for precision work

Press Selection Criteria