A bobbin case holds the bobbin and usually has some mechanism to control the tension of the thread as it pulls off the bobbin. Each machine has a specific bobbin case. The customer should match the model number and name of machine to determine which case must be used. The bobbin case may also be called a bobbin holder or bobbin shuttle. The bobbin is used to hold the bottom thread and is necessary for the machine to sew.
Every machine has a specific bobbin, based on make, model and name.
This information can be found in the customer instruction book. The bobbin is also known as the shuttle or the lower thread. In some cases, prewound bobbins are available. Bobbin Winders Devices that wind bobbins. Model number and name necessary to order.