Pattern materials — why aluminium is popular for patterns Why is aluminium widely preferred for making foundry patterns and core boxes for production work?

Introduction / Context:
Pattern material selection affects cost, dimensional stability, and productivity. Wood, plastics, and metals are used; aluminium often stands out in medium-to-high production where durability and accuracy matter.

Given Data / Assumptions:

• Patterns must be strong yet light enough to handle, with good surface finish.
• They should resist moisture and wear from repeated ramming and stripping.
• Patterns may integrate core prints and require machining for accuracy.

Concept / Approach:
Aluminium combines several desirable properties: low density eases handling of large patterns; machinability permits precise surfaces and integrated features; good corrosion resistance reduces swelling or dimensional drift common with wood; and it accepts inserts and repairs. Although aluminium is not always the cheapest initially, life-cycle economy is attractive because it withstands repeated production cycles.

Step-by-Step Solution:
Evaluate weight: aluminium is light, reducing operator fatigue.Evaluate workability: it machines and polishes easily for accurate profiles.Evaluate durability: resists moisture-induced distortion; stable dimensions.Hence, the collective answer is “all of these”.

Verification / Alternative check:
Foundry practice guides list aluminium as a standard for production patterns and match plates due to its balance of weight, machinability, and corrosion resistance.

Why Other Options Are Wrong:

• Any single property alone understates why aluminium is chosen.
• “Cheapest of all” is not generally true; wood is cheaper initially, but aluminium offers longer service life.

Common Pitfalls:
Assuming cost alone dictates choice; total cost of ownership (durability, accuracy, rework) often favours aluminium.

Final Answer:
all of these