Why does my sewing machine keep breaking needles or skipping stitches?

Skipped stitches and broken needles have the same root: the needle is not where the hook expects it to be at the moment the hook comes round to pick up the loop. Everything below is a way that happens.

Safety

What you'll need

• A packet of new needles in the right type and size
• The machine manual, or the threading diagram on the machine
• A small screwdriver (optional)

Step by step

1. Unplug the machine, then fit a brand new needle.Needles are consumables and blunt long before they look it — every project, or roughly every eight hours of sewing. A needle that has hit a pin once is bent even if you cannot see it, and a bent needle is the most common cause of both faults.
2. Check it is the right way round and pushed fully home.On virtually every domestic machine the flat side of the shank faces the back and the long groove faces you. Push it up until it stops before tightening. A needle set even a millimetre low puts the eye out of line with the hook, which is exactly what makes stitches skip.
3. Match the needle point to the fabric.Ballpoint or jersey for anything knitted, because a sharp point pierces the loops and cuts them. Sharp or microtex for fine, densely woven fabric. Universal for ordinary wovens. Jeans or denim for heavy layers. Leather needles have a cutting point and must never be used on fabric.
4. Match the needle size to the thread and fabric.A fine needle in heavy fabric bends and breaks; a heavy needle in fine fabric leaves holes. Roughly: size 70 to 80 for light fabric, 80 to 90 for ordinary dressmaking, 90 to 100 for denim and canvas.
5. Stop pulling the fabric through.Guide it, do not pull. Pulling drags the needle sideways so it strikes the needle plate or the hook. It is also what breaks needles on curves, when people help the fabric round the corner.
6. Slow down, especially over thick seams.Racing over a folded jeans hem is a guaranteed break. Turn the handwheel by hand through the thick part, or use a levelling shim under the back of the foot so the foot stays horizontal.
7. Look at the needle plate and the foot.A burr or a nick in the hole of the needle plate deflects the needle and shreds thread. Run a fingernail round the hole. A damaged plate needs replacing; smoothing it yourself usually makes it worse.
8. Rethread the whole machine with the presser foot up.Skipped stitches can also come from the top thread not sitting in the tension discs, which only open when the foot is raised. Rethreading costs a minute and eliminates a whole class of fault.
9. Check the bobbin area for lint and thread.A wad of lint under the bobbin case, or a thread caught in the hook race, changes the timing of the pickup. Unplug, remove the bobbin case if your machine allows it, and brush it out — do not blow into it, which drives lint further in.
10. Test on a doubled scrap of the same fabric.Every time, before touching the garment. If the test stitches are clean and the garment is not, the difference is in what the fabric is doing, not the machine.

Tips

• Write the needle type and size on a sticky label on the machine when you change it. Nobody remembers what is fitted.
• If the machine sounds like it is punching rather than stitching, the needle is blunt.
• Never sew over pins. A struck pin bends the needle, chips the hook, and sends fragments.

Common mistakes

• Using the same needle for months — A needle blunts and develops a burr long before it looks damaged, and a blunt needle needs far more force to enter the fabric — which is what deflects it, snaps it and skips stitches.
• Helping the fabric through by pulling it — It deflects the needle sideways into the plate. The machine's feed dogs move the fabric at the right speed; your job is only to steer it.

If it doesn't work

Questions people ask