CUPAL technical datasheet — full specification

This datasheet contains the complete technical specification of the CUPAL Elektro-Cupal-Blech 70/30 (soft) copper-aluminum bimetal composite material. If what you need is not a material property but a part number from a drawing or a bill of materials, the CUPAL part number cross-reference maps those designations onto our own sizes and SKUs.

General data

Property	Value
Material type	Cold-roll-bonded composite (Verbundwerkstoff)
Composition	70% Aluminum / 30% Copper
Supplier / distributor	WMH Westdeutscher Metall-Handel GmbH, Germany (Hungarian distributor: HIDRA-MIX Kft., Budapest)
Manufacturing process	Cold-roll-bonding (Kaltwalzplattieren) + diffusion welding

Physical properties

Property	Value	Unit
Density	4.6	g/cm³
Electrical conductivity	41.9	m/(Ohm·mm²)
Specific electrical resistance	0.0239	Ohm·mm²/m
Thermal conductivity	265	W/(m·K)
Linear thermal expansion	21.8	10⁻⁶/K

Mechanical properties

Property	Value	Unit
Modulus of elasticity (Young's modulus)	81	kN/mm²
Tensile strength	130–180	N/mm²
Bond strength (Haftfestigkeit)	70–110	N/cm band-width
Max. heat-treatment temperature	260	°C
Max. heat-treatment duration	4	hours

Surface hardness

Side	Vickers hardness	Brinell hardness
Aluminum side	30–40 HV 0.2	30–40 HB 2.5/62.5
Copper side	50–70 HV 0.2	50–70 HB 2.5/62.5

Chemical composition

Aluminum component

Property	Value
Grade	AL 99.5
Material number	3.0255 (DIN 17007)
International designation	Alloy 1050A
Purity	min. 99.5% Al

Copper component

Property	Value
Grade	E1-Cu58
Material number	2.0065 (DIN 1787)
French standard	CU/a1 (NFA 53-100)
Purity	Cu 99.9%

Conductivity comparison

Material	Conductivity	Relative (vs Cu)	Density
Pure copper	~58 m/(Ohm·mm²)	1.00	8.96 g/cm³
CUPAL 70/30	41.9 m/(Ohm·mm²)	0.72	4.60 g/cm³
Pure aluminum	~36 m/(Ohm·mm²)	0.62	2.70 g/cm³

Cross-section factors:

Required cross-section vs. copper: 1.41×
Required cross-section vs. aluminum: 0.906×

Standard sheet sizes

Thickness	Dimensions	Approx. sheet weight
0.5 mm	500 × 2000 mm	~2.25 kg
1.0 mm	500 × 2000 mm	~4.40 kg
1.5 mm	500 × 2000 mm	~6.70 kg
2.0 mm	500 × 2000 mm	~9.00 kg

Surface-finish options

Type	Description
Walzblank	Mill-rolled finish (standard)
Blank	Polished, bright finish
Gebürstet	Directional brushed
Satiniert	Fine satin texture
EDT (isotropic)	Electrical-discharge textured, uniform, directionless

Edge specification

Standard: cut edges (Geschnittene Kanten, GK)

Processability

Cold forming

Full range of cold forming possible: bending, deep drawing, embossing, stretch forming, edge bending, profiling, beading, riveting, hemming.

Joining technology

Soft-soldering: on the copper side with standard processes
Plating: on the copper side with standard galvanic processes
Bolted joints: primarily for electrical applications

Heat-treatment limit

Maximum 260 °C temperature
Maximum 4 hours duration
Purpose: relieving work-hardening
Exceeding the limit: uncontrolled intermetallic-layer growth

CUPAL material standards

The material's own standards (not application-area standards):

Component / aspect	Standard
Aluminum component (AL 99.5)	DIN 17007 / Werkstoff-Nr. 3.0255
Copper component (E1-Cu58)	DIN 1787 / Werkstoff-Nr. 2.0065
Supplier quality management	ISO 9001:2015

CUPAL transition elements are typically used in equipment built to DIN 43671, IEC 61439, IEC 61238 or IEC 62305 — but these are equipment standards, not CUPAL material standards. For details, see CUPAL material and application-area standards (DIN, IEC, MSZ EN).

Delivery and storage

Worldwide delivery
Small quantities orderable (Kleinstmengen)
Custom cutting on request
Store in a dry, well-ventilated environment

Questions about technical parameters? Request expert advice.

Frequently asked questions

CUPAL 70/30 has a specific electrical conductivity of 41.9 m/(Ohm·mm²) and a specific electrical resistance of 0.0239 Ohm·mm²/m. That is about 72% of pure copper's conductivity (~58 m/(Ohm·mm²)), so for the same current a 1.41× larger cross-section is required compared with copper.

CUPAL 70/30 has a density of 4.6 g/cm³. This is well below pure copper's 8.96 g/cm³, so a CUPAL part performing a copper-equivalent task is significantly lighter.

Standard sheet thicknesses are 0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm, all in 500 × 2000 mm size. Sheet weight ranges from approx. 2.25 kg to 9.00 kg depending on thickness. Custom cutting is available on request.

The maximum heat-treatment temperature is 260 °C for up to 4 hours (to relieve work-hardening). Exceeding this leads to uncontrolled intermetallic-layer growth.

CUPAL 70/30 consists of 70% aluminum and 30% copper. The aluminum component is grade AL 99.5 (min. 99.5% Al, material number 3.0255) and the copper component is grade E1-Cu58 (Cu 99.9%, material number 2.0065). The two metals are joined by cold-roll-bonding (Kaltwalzplattieren) and diffusion welding.

Tensile strength is 130–180 N/mm², the bond strength (Haftfestigkeit) between the copper and aluminum layers is 70–110 N/cm band-width, and the modulus of elasticity is 81 kN/mm². The material is suitable for full cold forming.