The lower parts of the sewing machine arm include the feed dog, feed dog lifter, needle bar, and needle plate. The feed dog moves the fabric through the machine and the feed dog lifter raises and lowers the feed dog. The needle bar holds the needle and moves it up and down to pierce the fabric. The needle plate provides a surface for the fabric and has a hole for the needle.

1. Parts of the Sewing Machine in the Arm:

2. The Lower Parts of the Lock Stitch Sewing Machine