Question

A cylindrical cup of $48.5mm$ diameter and $52mm$ height has a corner radius of $1.5mm$. Cold rolled steel sheet of thickness $1.5mm$ is used to produce the cup. Assume trim allowance as $2mm$ per $25mm$ of cup diameter. What is the blank size in $mm$?

• A. $102.0$
• B. $115.4$
• C. $120.5$
• D. $128.5$

Answer 1

The correct option is B $115.4$

Here, we have
$48.5$ (cup dia) $>20r=20\times 1.5=30mm$
So, Blank size $=\sqrt{d^2+4dh}$
$=\sqrt{(48.5{)}^2+4\times 48.5\times 52}=111.53mm$
$\text{Trim allowance}=\frac{2}{25}\times 48.5=3.88mm$
$\text{Total blank size}=111.53+3.88=115.41mm$