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Sewing machine jargon buster

By Jess O'Leary

Do you know your bobbin from your feed dog? We get to the bottom of sewing machine terminology and explain what’s what.

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Most electric sewing machines have the same common components, such as a motor that drives the needle and a bobbin, feed dog and needle plate.

Features such as a buttonhole maker and knee lifter are added extras that allow you to do more or that make life easier.

If you need a new machine, we’ve got in-depth brand reviews for all of the big manufacturers, such as Singer, Janome and Brother. Our customer scores and star ratings are based on what real-life owners think of their machines and can help you compare the various brands you’ll see in the shops. To see the full profiles, check out our best sewing machine brands.

Sewing machine parts and features

Sewing machines use two separate threads to make a stitch: the needle thread, which comes down from the top of the machine, and the bobbin thread, which comes up from the bottom. Many parts work together to create a successful stitch.

Below are the main sewing machine parts, features and terms you'll come across.   


A bobbin is a small spool for holding the thread in the bottom of the sewing machine; it sits in a compartment under the needle. Thread needs to be wound onto the bobbin before you start sewing. Most electric machines have a bobbin-winding function.

Bobbins in older sewing machines load from the side and usually sit inside a metal case, which helps to control the tension in the thread.

New sewing machines often have a drop-in bobbin, which loads from above. Sometimes they have a see-through cover over the bobbin compartment, which makes it easier to see how much thread is left.

Thread is wound onto a bobbin before you start sewing.

Feed dog

The feed dog is a metal plate with tiny metal teeth that stick up through the plate under the sewing machine's needle. They feed fabric from the front to the back of the machine.

As the needle comes up out of the fabric after making a stitch, the feed dogs rise up and grip the fabric against the presser foot, then slide backwards and pull the fabric with them.

Some sewing machines have a ‘drop feed dog' function. This means that you can fix the feed dog in the down position, letting you move the fabric manually under the needle in the direction you choose. This is useful for embroidery and mending.

For advice on which type of machine is right for your sewing needs, head to our sewing machine buying guide.

Presser foot

The presser foot holds the fabric flat under the needle and in place against the feed dog. This helps feed it through evenly as you sew.

There's a range of different presser feet available, designed to do different jobs, such as inserting a zip or sewing blind hems.

Presser feet are either held in by a screw or a foot-holder clip, which makes them easier to change.

Sewing bed

This is the bottom part of the backwards ‘C' of the sewing machine. It's often made of two parts:

  • The free arm is a protruding cylinder that can be used to sew smaller or tubular pieces of fabric such as pockets and sleeves. The bobbin is loaded into this part of the machine
  • The extension table fixes around the free arm to create a wide, flat area that is more suitable for supporting and controlling large pieces of fabric.

It's good to have a sewing bed that's curved slightly at the front, as this helps you to feed the fabric smoothly.

Sewing machine needle plate

The needle plate fits over the feed dog on the bed of the sewing machine and covers the bobbin. It also has a hole that the needle passes through.

Needle plates often have a series of lines etched on them to indicate the distance away from the needle. They can be used as a guide to help you sew in a straight line, and also to keep your stitches a set distance away from the edge of the fabric.

Markings on the needle plate can help you to sew in a straight line.

Bobbin winder

This small pin that sticks out of the top of the sewing machine is used to load thread onto the bobbin.

It's fairly common for the action of clicking the winder into place to disengage the needle so it doesn't move up and down as the bobbin is winding, and for the bobbin to stop loading when it is full. 

However, on cheaper sewing machines you may need to de-clutch the needle manually and decide when to stop loading the bobbin for yourself.

Spool holder

This is the pin at the top of the sewing machine where you place the reel of thread. 

It's useful to have a couple of spool end caps of different diameters – these are the plastic discs that hold the reel in place and help to feed the thread.

Some sewing machines have two spool holders, so you can sew with two different coloured threads at the same time with a twin needle.

Foot pedal

A sewing machine is driven by a belt inside that synchronises the moving parts to work together to form stitches. The speed of the belt is controlled by a foot pedal – the machine speeds up as you press down on the pedal.

Some sewing machines have a switch that allows you to select low or high speed settings, which gives you more control of the speed than the foot pedal alone.

The harder you press the foot pedal the faster the machine will sew.

Stitch selector

Sewing machines each have a range of stitches to choose from, which are often displayed on the side of the sewing machine or on the stitch-selector dial.

Basic sewing machines have a dial that you turn to select the stitch you want, while more expensive machines let you select a stitch by pressing a button or using a touchpad. Both types are usually illustrated to show you the stitch that you're selecting.

Some cheaper models treat different lengths of straight stitch, or the individual sides of a buttonhole, as an individual stitch choice.

All but the most basic entry-level sewing machines usually give you the option to vary the length and width of your stitches.

Tension control

Most sewing machines have a tension-control dial that's used to control the tension of the upper thread. This is important to help stitches form correctly.

Some dials have the tension for the most commonly used stitches highlighted on them.