A sewing machine skips stitches when the hook misses the loop of top thread behind the needle, and the cause is almost always the needle: it is dull, bent, the wrong type for the fabric, or not pushed all the way up in the clamp. Fit a new needle of the right type, a ballpoint or stretch needle for knits and a universal or microtex for wovens, re-thread the machine with the presser foot raised, and the skipping usually stops. If it continues, the next suspects are the thread, the presser foot pressure and lint in the bobbin area.
Where and when does it skip?
The pattern of the skips tells you where to look.
| Symptom | Most likely cause | Fix |
|---|---|---|
| Skips on knits, fine on wovens | Universal needle pushing the knit down instead of piercing it cleanly | Ballpoint (jersey) needle 75/11 or 80/12, stretch needle on fabrics with elastane |
| Started suddenly mid-project | Needle blunted or bent, often from hitting a pin | New needle; sew over no pins |
| Skips over thick seams and seam crossings | Foot tilting and needle deflecting on the step | Level the foot with a folded scrap behind it, hand-walk the crossing, jeans needle 90/14 or 100/16 |
| Skips on sheers and silks | Needle too thick, fabric fluttering in the plate hole | Microtex 60/8 or 70/10, stitch 2 mm (12 per inch), tissue paper or a straight-stitch plate |
| Skips with metallic or topstitching thread | Needle eye too small for the thread | Topstitch needle 90/14 or 100/16 |
| Skips with every fabric and a new needle | Needle in backward or not fully up, wrong needle system, or hook timing | Re-insert flat side to the back; check the needle system; technician |
| One row of a twin needle skips | One of the pair is dull or the wrong type | Replace the twin needle with a stretch twin for knits |
| Skips with thread breaking and looping after a jam | Bent needle bar or moved timing | Technician |
Why does a sewing machine skip stitches?
Each stitch is a small piece of timing. The needle goes down through the fabric, rises a few millimeters, and the friction of the fabric on the thread forms a loop on the long groove side of the needle, where the scarf is. The hook sweeps past at exactly that moment and catches the loop. Anything that makes the loop form too small, too late or on the wrong side lets the hook pass through empty, and the machine lays a long straight length of thread with no lock in it: a skipped stitch.
That is why the needle is the first suspect. Its point, its scarf and the height it sits at all decide where and how big that loop is. The thread tension, the bobbin and the presser foot come after, because they decide whether the fabric stays still while the loop forms.
Is the needle the problem?
Four things to check, in order:
- Condition. A needle lasts about eight hours of sewing, less on heavy or synthetic fabrics. Run a fingernail down it; a hooked tip or a slight bend you cannot see with the eye will still skip. A needle that has hit a pin is finished even if it looks fine.
- Type. Universal needles have a slightly rounded point meant for most wovens. Ballpoint or jersey needles have a rounder point that slips between knit loops instead of cutting them. Stretch needles add a shaped scarf and a shorter eye that help the loop form on elastic fabrics such as swimwear lycra, ribbing and anything with elastane. Microtex needles have a sharp point for silk, microfiber and tightly woven fabric; jeans needles have a sharp point and a stiff shaft for denim and canvas. The needles and thread guide matches each one to its fabric.
- Size. Too fine a needle flexes on heavy fabric and misses the hook; too thick a needle on a sheer fabric makes a hole the fabric flutters in. 70/10 for light wovens, 80/12 for medium, 90/14 for heavy, and match the thread to the eye.
- Insertion. Household machines take needle system 130/705 H. Push the needle all the way up to the stop in the clamp, flat side of the shank to the back on nearly every domestic machine, and tighten the clamp screw firmly. A needle that sits 1 mm (1/32 in) low changes the timing between the loop and the hook.
Why does my machine skip stitches on knit fabric?
Knits are the most common complaint, and the reason is flagging. The fabric is elastic, so when the needle pushes down the knit stretches down with it, and when the needle rises the fabric springs back up with it. The thread never gets a chance to form its loop, and the hook finds nothing. Thicker, bouncier knits such as French terry, sweatshirt fleece and rib do it most.
Three things stop flagging. A stretch needle, because its scarf gives the hook a bigger target. A straight-stitch needle plate, or on a machine without one the foot pressed closer to the plate by raising the presser foot pressure, so the fabric cannot lift with the needle. And a walking foot, which feeds the top layer as well as the bottom and keeps both in contact with the plate. The guide to sewing knit fabrics on a regular machine covers stitch choices as well, because a narrow zigzag, 0.5 mm wide and 2.5 mm long, also survives the odd missed stitch better than a straight stitch.
Why does my machine skip stitches over thick seams?
When the presser foot climbs onto a crossing of seams, as at the side seam of a jeans hem or the corner of a tote bag, the back of the foot is lower than the front. The foot tilts, the fabric under the needle is no longer pressed to the plate, and the needle itself is deflected sideways as it enters the slope. Both make the hook miss.
Level the foot before you climb: stop with the needle down at the foot of the step, lift the foot, slide a folded scrap of the same fabric under the heel of the foot so it sits flat, lower it and carry on slowly. A plastic hump jumper does the same. On the far side, repeat under the toe. For denim, a jeans needle and a stitch length of 3 mm (8 per inch) help, as sewing with denim explains.
How do you fix skipped stitches step by step?
Work down the list and test after each step on a doubled scrap of the fabric you are sewing, at a medium, even speed.
- Fit a new needle of the right type and size, pushed fully up, flat side to the back, clamp tight.
- Re-thread top and bobbin with the presser foot raised, making sure the thread is in the take-up lever. Check that the bobbin thread is under the case's tension spring.
- Match the threads. Use the same all-purpose thread top and bobbin. A fuzzy, old or very thick thread does not form a clean loop.
- Clean the bobbin area and look at the needle plate hole under good light. A burr from a broken needle catches the loop; smooth it with fine emery paper or replace the plate. Cleaning and oiling the machine takes ten minutes.
- Adjust the presser foot pressure. More pressure for knits that flag, less for thick stacks the foot cannot climb. The dial is on top of the machine on most mechanical models and in a menu on computerized ones.
- Change the plate or the foot. A straight-stitch plate for fine fabric and knits, a walking foot for anything that shifts.
- Slow down and keep a steady speed through seam crossings and curves. Lurching from fast to slow changes how the loop forms.
- If nothing helps, and every fabric skips with a new needle and clean threading, the hook timing or the needle bar height has moved, usually after a hard jam. That is a technician's adjustment on a modern machine.
Tip: Buy needles in the size you use most by the box of ten and change them at the start of each new project. It is the cheapest maintenance there is, and it takes a minute.
If you are sewing a pattern and are not sure which needle its fabric wants, the sewing guide that comes with a Sewly pattern can be asked ("which needle for this jersey?") and answers for the fabric and garment you are making.