The document lists and describes 17 key parts of a sewing machine: 1) The spool pin holds the thread spool. 2) The thread guide positions the thread from spool to needle. 3) The tension discs adjust thread tension via a spring and nut. 4) The take up lever feeds and tightens the thread loop. 5) The needle bar holds and moves the needle. 6) The bobbin case catches the top thread to form stitches. 7) The presser foot holds the cloth firmly.