GATE 2016 ME (ME2) – Question 59

Casting, Forming and Joining Processes · Casting: patterns, moulds, cores, solidification, riser and gating design, defects · 2 marks · Numerical answer

Gray cast iron blocks of size 100 mm × 50 mm × 10 mm with a central spherical cavity of diameter 4 mm are sand cast. The pattern shrinkage allowance is 3%. The ratio of pattern volume to casting volume is ______.

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Correct answer: 1.08 to 1.10

Explanation

A3% shrinkage allowance increases each linear pattern dimension by factor1.03. Hence its corresponding volume scales by1.03³=**1.092727**. Apply the same geometric scale consistently to the specified shape, including the cavity representation. The requested ratio is a volume ratio, not1.03.