The tip of a sewing needle is sharp because the area under the pointed end of the sharp needle is very small. Pressure exerted by a sharp needle is more on the cloth and can pierce easily through the cloth.

Why are needles pointed?

Pressure is inversely proportional to area. A pointed tip will have a very small area. So, when we try to sew or pin up the papers, we apply force over a very small area, and this results in a large pressure. This makes it easy to sew or pin up the papers.

What are sharp needles?

The sharp needle (or 'sharp') is a type of needle used for general hand sewing, including decorative needlework. The sharp needle has a sharp point, rounded eye and is of medium length (generally between 4 and 5 cm). It is sometimes also called an appliqué needle.