Lesson plan
Pattern (casting)
s In casting, a pattern is a replica of the object to be cast, used to form the sand mould cavity into which molten metal is poured during the casting process. Once the pattern has been used to form the mould, the pattern is then removed and molten metal is poured into the cavity to produce the casting. The pattern is non-consumable and can be reused to produce further sand moulds almost indefinitely. Due to the fact that almost all metals contract or shrink as their temperature falls, casting patterns must be made larger in size than the actual casting they will produce. Aluminium casting contraction is ~1.3% for example, so patternwork for a cast aluminium part would be made 1.3% bigger than the cast part itself. Patterns used in sand casting may be made of wood, metal, plastics or other materials. Patterns are made to exacting standards of construction, so that they can last for a reasonable length of time, according to the quality grade of the pattern being built, and so that they will repeatably provide a dimensionally acceptable casting.
Article summary
s In casting, a pattern is a replica of the object to be cast, used to form the sand mould cavity into which molten metal is poured during the casting process. Once the pattern has been used to form the mould, the pattern is then removed and molten metal is poured into the cavity to produce the casting. The pattern is non-consumable and can be reused to produce further sand moulds almost indefinitely. Due to the fact that almost all metals contract or shrink as their temperature falls, casting patterns must be made larger in size than the actual casting they will produce. Aluminium casting contraction is ~1.3% for example, so patternwork for a cast aluminium part would be made 1.3% bigger than the cast part itself. Patterns used in sand casting may be made of wood, metal, plastics or other materials. Patterns are made to exacting standards of construction, so that they can last for a reasonable length of time, according to the quality grade of the pattern being built, and so that they will repeatably provide a dimensionally acceptable casting.
Key claims
No claims recorded.
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.