Question

why tip of thumb pin is made sharp

Answer 1

the tip of a thumb pin is made sharp so that it can be easily get into anything by making a hole from the fact that when area reduces pressure increases.and when area increases pressure reduces.since, area of tip of a thumb nail is very less therefore pressure is more and it can easily make a hole.
        i hope that this will help u........................^_^

Answer 2

Tip of pin is made sharp so that pressure applied on the surface will be larger as well as easy to  go insert it on any object....