Anatomy of a Sewing Machine

Are you new to sewing or want to learn more about how your machine works? Understanding the parts of a sewing machine and how they work will help you troubleshoot potential issues and become a better, more self-reliant sewer. This glossary of sewing parts defines the components and areas common on almost all sewing machines. Even if you don’t own a Sailrite® machine, you should be able to locate these parts on your machine.

Note: Please consult your owner’s manual for specific information regarding your machine.

Sewing Machine Parts & Terms

Arm: The top part of the sewing machine. It’s comprised of all the internal components that drive the needle into the fabric.

Balance Wheel: Also known as a hand wheel or flywheel, the balance wheel is located on the right side of the sewing machine and helps regulate the rate of movement of the sewing machine parts.

Bed: The flat bottom of the sewing machine. If your machine is housed in a table or case, the bed should rest slightly proud of the table or case.

Bobbin: A spool that sits in the lower part of the machine holding the thread that makes the underside of a stitch.

Clutch Motor: A clutch motor runs continuously. The sewing machine is started with a treadle-activated clutch and stopped by a heel-operated brake. 

Compound Feed: A walking foot and needle feed system that provides optimal fabric control. The needle penetrates the fabric and then moves back with the material and walking foot. Also known as a compound walking foot.

Domestic/Home Machine: A lightweight, portable machine designed for home use and casual sewers. They can be mechanical or computerized. 

Drop Feed: Feeding mechanism in which the feed dog moves forward and back to move fabric when the needle is out of the assembly after creating a stitch. The most common type of feeding mechanism in a home sewing machine. 

European Power: Powered for use outside the United States, these sewing machines are equipped with a 220-240VAC motor and power cord with a standard continental European plug end.

Feed Dog: Metal teeth that travel in an oval pattern within the needle plate opening to grip, feed and release the fabric being sewn. Each rotation provides incremental fabric movement while stitches are being created.

Foot Control: Allows for consistent variable speed control of the sewing machine’s motor.

Gib Hook: A hook that rotates around the cage that holds the bobbin thread under the machine. The hook catches the loop of thread formed during needle retraction and further carries the thread to create the loop or knot, ultimately forming a stitch. 

Industrial Machine: Heavy-duty, nonportable machine designed to be used by job shops for mass production of sewn goods. Built to operate at high speeds and run for long periods. Industrial machines can handle heavy fabrics and thick materials. 

Jack Drive (Idler Pulley): A steel machined pulley that increases gearing to provide more torque and slow speed to a machine.

Knee Lift: A linkage often found on industrial sewing machines that makes it possible to lift the presser foot of a sewing machine with your knee.

Mechanical Walking Foot: A foot that moves forward and back in time with the feed dog — when the needle is out of the material — to ensure that layers of fabric are consistently moving together through the machine.

Needle Bar Stroke: The range of movement of the needle up and down. In general, a longer stroke makes a sewing machine more capable in thick fabric assemblies.

Needle (Throat) Plate: The flat surface below the presser foot that provides an opening for the needle to go up and down and allows the feed dog to reach the fabric. 

Needle Positioning Lever: Allows for left, right and center positioning of the needle on zigzag stitch sewing machines. Zippers are easier to install and often do not require separate zipper feet on machines with this feature.

Needle System: Although there are hundreds of different needle systems, every sewing machine has a compatible needle system specific to that machine. It is important to know your sewing machine’s needle system when you purchase needles.

Power Stand: Table designed for industrial sewing machines. A motor is typically mounted beneath the table.

Presser Foot: A foot or feet that hold(s) the fabric down as it is being stitched.

Presser Foot Tension: Adjustable spring tension on the presser foot to hold the material captive.

Puller Feed: A modification of the drop feed system. A supporting roller applies downward pressure to drag the assembly through the machine at the same time as the feed dog.

Reverse Lever: Pulling down on the lever activates the reverse function for backstitching.

Safety Shear/Clutch: A fail-safe that protects the machine from internal damage should you experience problems while sewing.

Servo Motor: Acts similar to a clutch motor except the motor only runs when engaged, resulting in a quieter, lighter and more energy-efficient motor with variable speed control. However, slow speed power in heavy fabric assemblies is poor without gear reduction. 

Shuttle: Generically known as the hook region of a sewing machine.

Spool Pin: A small dowel or post that holds the thread spool in place while the machine feeds the thread. 

Stitch Length: The total length of one stitch measured in millimeters. 

Stitch Length Dial: Allows for the adjustment of stitch length. Rotate the dial to increase or decrease stitch length.

Stitch Length Lever: Allows for the adjustment of stitch length. Pulling the lever all the way down results in a backstitch.

Straight Stitch: A line of stitching that appears to be straight and upon close inspection is a series of line (stitch) segments that follow one after the other.

Take-Up Arm/Lever: Sewing machine part that pulls the thread up after each stitch, leveraging the tension assembly that applies tension to each stitch knot. Visibly moves up and down.

Tension Assembly: Dial adjusted spring pressure device that applies friction to the upper sewing thread, creating the proper stitch quality (tightness).

Throat: The open window of space to the right of the needle. It’s also the length of the machine’s arm. The larger the throat, the more fabric you can fit underneath the machine. Industrial machines have a larger throat clearance for sewing large and bulky assemblies.

Universal Motor: An electric motor that can run on either AC or DC power. 

WorkerB Motor: The most powerful nonindustrial machine motor. 2.5 times more powerful than a universal motor. Only available on Ultrafeed Sewing Machines.

Zigzag 2-Point (1-Step) Stitch: Lateral movement of the needle bar with entry and exit at each extreme left and right of each movement. As the name implies, the stitch formation looks like a zigzagging line of thread.

Zigzag 4-Point (3-Step) Stitch: Lateral movement of the needle bar with entry and exit at two points along the movement and at the extreme left and right of each movement. This three-step stitch results in each zig or zag comprising of three distinct line (stitch) segments.

If you’re in the market for a sewing machine, you’re in the right place! Sailrite machines are known for their quality, performance and reliability. All our sewing machines are mechanical. They are easy to operate and great for beginners. Our flagship machine, the Sailrite Ultrafeed, is a walking foot machine with the most powerful motor available on a portable machine. Visit our sewing machines landing page to learn more about our four machines and to find the right one for your DIY journey.

And we’re not just an online store! Sailrite is your source for quality sewing materials and supplies, as well as the best free DIY content on the internet. Click here to browse hundreds of project videos, sewing tips and tricks articles, and product reviews to make your DIY dreams a reality.