A sewing machine throat plate is the metal plate beneath a sewing machine's needle and presser foot. It is typically held in place with one or more screws.
- A sewing machine throat plate has holes or slots for the needle to pass through as it moves up and down to stitch the fabric to accommodate the different needle positions and fancy stitches available on the machine.
- A throat plate has a second, larger, opening (or two) that allows the sewing machine feed dogs to emerge from below to grip the fabric and help move it forward as you sew. Remember that feed dogs can be lowered for some tasks, such as freehand quilting techniques and darning.
- It's easy to see the feed dogs stretching upwards through rectangular openings in the plate shown in the photo.
- A throat plate also provides a smooth surface for the fabric as it passes through the machine.
Do All Throat Plates Look Alike?
Sewing machine throat plates can look very different, depending on the type of sewing machine they are designed to fit.
- Some plates are rectangular, like the plate visible under the pressure foot in the photo.
- Some have one straight side with an oval extension, usually to the right.
- Other throat plates can be entirely oval, and other shapes are used, too.
- You'll find a huge variety of throat plates when you shop for sewing machines.
What Are the Markings on Sewing Machine Throat Plates?
Throat plates are usually marked with closely spaced, grooved lines to the right (and often to the left) of the plate's center. The grooves are guidelines for seam allowances of varying width.
You might find that the grooves are perfectly accurate for some types of sewing, but quilters use a narrow 1/4" seam allowance and shouldn't assume that the plate markings are accurate. Even if markings are accurate, it's best to test your seam allowance and create a slightly elevated buffer for fabrics to butt against as they pass through the machine.
Most quilters prefer to depend on quarter inch presser foots when they make quilts, but even specialized pressure feet must be tested for accuracy.
Can I Remove the Sewing Machine Throat Plate?
Throat plates should be removed when it's necessary to clean the area underneath, which tends to become filled with lint as thread and fabric pass through the machine.
Some sewing machine throat plates must be removed to access the machine's bobbin. These plates are generally made in two parts. The part that must be removed is easy to click open without loosening a screw.
Can Throat Plates Cause Problems?
Make sure the bobbin thread isn't stuck underneath the pieces you are sewing when you begin to sew a seam. Pull threads away from the bobbin area to keep the needle and feed dogs from pushing them under the throat plate, where they can cause jams (and sometimes a big swirled glob of thread on the back side of your patchwork).
Machine quilters bring the bobbin thread to the top of their quilt sandwich before beginning their quilt, for the same reason.
Chain piecing can help you avoid jams since patchwork units are sewn one after the other without breaking threads between pieces.