What is aluminium cast tooling plate?

Aluminium cast tooling plate is produced through a continuous horizontal casting process, resulting in a uniform fine-grain microstructure. Its two primary faces are machined to a surface finish of Ra 0.4 – 0.8 μm and typically protected with a thin polycoat film.

In the UK, cast tooling plate is most commonly available in variants of the 5000 series aluminium alloys. Though versions also exist in the 6000 and 7000 series, these are less readily sourced in the UK market.

Unlike conventional rolled aluminium plate, which is forged from wrought ingots and then heat treated, cast tooling plate is manufactured close to final thickness. After casting, it is heat treated at over 370°C for approximately 10 hours to fully anneal and relieve internal stresses. A final light machining process ensures dimensional accuracy, and protective film is then applied.

Aluminium cast tooling plate is widely used in machine building, jigs, and fixtures due to its reliable performance in the following areas:

• Stable base material: Offers a flat, machined surface ideal for low to medium duty applications.
• Dimensional reliability: Maintains stability even when large volumes of material are removed during machining.
• Thermal consistency: Performs well in environments involving cyclical heating and cooling.

Machinability

Aluminium cast tooling plate offers excellent machinability, thanks to its uniform structure and dimensional stability. Compared to wrought aluminium, it has reduced material stickiness, though consistent flood coolant application is still advised.

Its slightly harder and more brittle nature means it is well-suited to delicate and intricate parts but may chip at entry and exit points of cuts. Reducing feed rate at these points can help avoid chipping. Thread milling is also recommended over tapping for better results when creating threaded holes.

Similar or obsolete designations and trade names

• 5000 Series: ACP5080, ACP5080R, ACP5754, ACP5754R, Alca 5, ATP-5, CAL5, C250, Kastal 300, K-100S
• 6000 Series: ACP6000 (Not readily available in the UK)
• 7000 Series: ACP7, ACP7R, MIC6 (Not readily available in the UK)

Main attributes

• Very low porosity
• Good tensile strength
• Good ductility
• Stress free condition similar to condition “0” temper wrought plate
• Ra 0.4 - 0.8 ųm finish to main faces, typically protected with thin polycoat film
• Very good flatness, typically 0.15 - 0.5 mm dependent on area of plate
• Very good machinability
• Excellent dimensional stability even when heavily machined
• Excellent base material to start machining manufacture
• Excellent mechanical and dimensional stability when repeatedly heated and cooled in its application of use
• Annealing after machining is not required
• Good polishing characteristics
• Good anodising and hard anodising properties
• Excellent corrosion resistance
• Very good weldability

Finishing & treatments

Anodising 5000, 6000 and 7000 series cast tooling plate components is commonplace and the materials offer comparable anodising qualities to their wrought plate equivalents.

• Natural sulphuric anodise
• Colour sulphuric anodise
• Natural hard anodise
• Colour hard anodise (deep colour tints)
• The anodising offers good protection

See our Finishing Processes page for further information on services that we can facilitate.

UK stock sizes

Here are the standard stock sizes/colours for Aluminium Cast Tooling Plate in the UK. Please note we do not supply stock material, the information provided is purely for design and research purposes.

Typically supplied with plastic protective film on both main faces.

• Thickness range: 6.35mm (¼”) up to 50.8mm (2")
• Maximum standard length is: 3670.3mm (144 ½”)
• Maximum standard width is: 1841.5mm (72 ½”)

Surface finish Ra0.4μm

Thickness +/- 0.1 mm

Flatness tolerance is dependant on plate thickness:

• Up to 12 mm thick plate 0.8 mm or less (per square metre depending on manufacturer)
• 15 mm upwards 0.15 mm (per square metre)

Typical chemical composition

ACP 5080

5083 (AlMg4.5Mn0.7) according to DIN EN 573-3 3.3547

ACP 7

EN AW-7021 (AlZn5.5Mg1.5) according to DIN EN 573-3

Note for designers

The machined flat faces offer an excellent base for starting machining.

Although a thin polyfilm coating is applied on manufacture, with transportation and warehousing some scratches and dents to the main faces are common. Plate suppliers do not guarantee blemish free.

If components are to be plated or finished in other ways, discuss fixturing arrangements for the process with a competent processor and make detailed notes and reference points on manufacturing drawings.

Wire thread inserts or other thread insert variants (for example Tappex inserts) should be considered for small diameter threaded holes where:

• There are more demanding mechanical forces in the application
• Threaded holes are to be assembled and disassembled frequently
• If in operation assembles will vibrate or be stressed