Though sewing is something mankind has been doing since nearly the dawn of time, the practical sewing machine is a more recent invention, the first appearing in the 1800s. When you have a sewing machine to which you wish to add attachments, it's helpful to determine your sewing machine shank size. With this information, you can add attachments, such as ruffle or zipper feet, which can make your sewing machine all the more versatile. It can also help you to replace any part that may be broken, ensuring you get the properly sized piece.
Grasp the wheel, and turn it so that the needle is at the bottom position.
Lower the presser foot so that it rests on the bed of the machine.
Set the end of a ruler on the bed of the machine, inch end down.
Measure from the bed of the machine to the center mark on the thumb screw. This is the length of the shank.