Sewing machine needles – which one is right?

When sewing, the sewing machine needle and its quality deserve close attention. Unfortunately, you often cannot tell just by looking whether a needle is good, mediocre or poor. The appearance and quality of the seam, however, always tell you directly about the quality of the needle. The basic rule is therefore: “Only use high-quality needles!” Below you will find out what to look for when buying needles.

What makes a high-quality needle?

First of all: a cheap sewing machine from the supermarket will not sew cleanly for long, even with the best needle. So invest in a good sewing machine if you sew more than once a year.

A decisive quality factor is consistency from needle to needle, so that the sewing behaviour always stays the same. Good needles are designed to create as little friction as possible. Special attention is paid to the point and above all to the eye: the point creates friction when piercing the fabric, and an optimally shaped eye lets the thread glide through without chafing. Few people realise that with a lockstitch, for example, the thread is pulled back and forth through the eye under tension 20 to 60 times at the same spot. With poor needles the thread frays – at best this weakens the seam, at worst it causes thread breakage and a rejected seam.

In the 1970s and 1980s we compared the surface finish of needles from various manufacturers under high-resolution microscopes. Microscopic flaws and roughness on the needle surface also lead to more friction, more heat on the thread and ultimately to the dreaded thread breakage. Tests confirm it again and again: the SCHMETZ needles in our range are of the highest and most consistent quality.

The needle system – which needle fits the machine?

Industrial sewing machines use a wide variety of needle systems. Household sewing machines are simpler: they almost exclusively use the systems 130/705 H (flat shank) and 287 WH / 1738 (round shank). You will find more in the category “Needles for household sewing machines”.

Needle size – first the thread, then the needle!

The needle size is given as the blade diameter in “Nm” (metric number). 1 Nm equals one hundredth of a millimetre: a size Nm 80 needle is therefore 0.8 mm thick, a size Nm 120 needle has a blade diameter of 1.2 mm, and so on.

The right needle size must match the thread and the material being sewn. In industry, extensive test series with different needles and threads are usually carried out before production starts, assessing stitch and seam quality as well as needle service life.

The needle must be matched to the thread size so that the thread is not slowed down in the eye. If the needle is too thin, the thread is held back in the eye; higher thread tension is needed, which can lead to seam puckering, chafing and thread breakage. A needle that is too thick is also unfavourable, because the thread is not guided properly in the long groove, stitch formation becomes more difficult and skipped stitches are likely.

Avoiding skipped stitches

Skipped stitches often occur with extremely elastic fabrics, with layers of different thickness and with cross seams. Highly elastic fabrics, for example for swimwear, bras or bodysuits, tend to flag with the moving needle. With materials of different thickness – e.g. when going from two to four layers on jeans or when sewing tubular parts – the risk of skipped stitches increases further because the needle is deflected.

Needle manufacturers offer special needles for this, such as the SERV 7 from SCHMETZ. It has a hump in the scarf area and an additional blade reinforcement. The hump improves loop formation and so prevents skipped stitches; the reinforcement makes the whole needle more stable and clearly reduces deflection.

The needle point – the right point for every material

Basically, a distinction is made between round points and cutting points. Round points – depending on the version normal, slim or with a light to heavy ball – push the fibres or loops of woven and knitted fabrics aside without damaging them. Cutting points cut through the material and are used for leather and films.

The needle as a problem solver: a sewing machine needle should not only be of the highest manufacturing quality but also be chosen correctly. Your sewing machine determines the needle system – then choose the right point style and the size that matches the thread.

Happy sewing!