Question

A casting of size 100 m × 100 mm × 50 mm is required. Assume volume shrinkage of casting as 2.6%. If the height of the riser is 80 mm and the desired riser volume is 4 times the shrinkage in casting, what is the appropriate riser diameter in mm?

• A. 57.52
• B. 20.34
• C. 14.38
• D. 28.76

Answer 1

The correct option is D 28.76

$\text{Shrinkage volume of casting}$

$=\frac{2.6}{100}\times 100\times 100\times 50=13000m{m}^3$

Volume of riser should be 4 times of shrinkage Volume of casting

$V_r\text{= 4 × 13000 = 52000}m{m}^3$

$V_r=\frac{\pi }{4}{d}^{2}h=52000$

$d^2=\frac{52000\times 4}{\pi \times 80}$

$d=28.76mm$