The upper part of the needle that is inserted into the needle bar and locked into place with the needle clamp screw. The back side of the shank is flat and the front side is rounded. Lower part of needle below the shank. The needle size indicated refers to the diameter of the shaft. Hollowed out area on the front of the needle shaft just above the eye that permits thread to remain close to the needle during stitch formation.
Deeper grooves provide protection and reduce friction of the thread.
The open indentation behind the eye of the needle where the bobbin shuttle picks up the loop of needle thread to form a stitch. Opening just above the needle point through which the thread is placed. The size varies according to type and size of needle. Tip of the needle. The size and shape vary according to the needle type.