Information about sewing machine needles - which one is the right one?

When sewing with a sewing machine, it is important to pay close attention to the sewing machine needle and its quality. Unfortunately, it’s often not immediately apparent just by looking at a needle whether it’s good, average, or poor. However, you can always draw a direct conclusion about the needle’s quality based on the stitch pattern and stitch quality. As a general rule, therefore, you should always use only high-quality needles!
Below, you’ll learn what you should definitely look for when buying needles. 

What makes a high-quality needle?
First things first: A cheap sewing machine from the supermarket won’t sew neatly for long, even with the best needle. So invest in a high-quality sewing machine if you plan to sew more than just once a year.

A crucial factor in quality is the consistency from needle to needle, ensuring that the sewing performance remains consistent. With good needles, great importance is placed on minimizing friction as much as possible during sewing. Particular attention is paid to the design of the tip and, in particular, the needle eye, because the tip creates friction during the needle entry, and an optimally shaped eye ensures that the thread glides through smoothly and does not get caught on it. Very few sewers are aware of the fact that, for example, with a double-stitch, the sewing thread is pulled back and forth under tension through the needle eye 20 to 60 times in a single spot. With poor-quality needles, the thread then bunches up (fraying) and, at best, leads to a weakened seam—at worst, to a thread break and thus a defective seam.

In the 1970s and 1980s, we used high-resolution microscopes to compare the surface quality of needles from various manufacturers. Microscopic defects and roughness on the needle surface also lead to increased friction, more heat on the thread, and ultimately to the dreaded thread breakage. Tests show time and again: Our Schmetz needles are of the highest quality and consistently reliable! 

The needle system—which needle for which machine?
Industrial sewing machines use a wide variety of needle systems! Things are a bit simpler when it comes to household sewing machines, which almost exclusively use the 130/705 H (flat-shank) and 287 WH / 1738 (round-shank) systems. Visit the “Needles for Household Sewing Machines” category to learn more!

Needle size—first the thread, then the needle!
The needle size (or thickness) is specified as the diameter at the shank in “NM.” 1 NM corresponds to one hundredth of a millimeter. Consequently, an NM80 needle is 0.8 mm thick, an NM120 needle has a shaft diameter of 1.2 mm, and so on.

The correct needle size should be chosen based on the sewing thread and the fabric. In industrial settings, extensive test series are usually conducted with various needles and threads before production begins. These tests evaluate stitch and seam quality as well as the service life of the sewing needles used.

The sewing machine needle must be matched to the sewing thread’s cross-section so that the thread’s movement through the eye is not impeded. If the needle is too thin, the thread is slowed down in the eye, requiring higher thread tension, which can lead to puckering, fraying, or breakage. A needle that is too thick is also undesirable because the thread is not guided sufficiently through the long groove, making stitch formation more difficult and likely resulting in missed stitches. When working with materials of varying thicknesses—for example, when transitioning from two to four layers in denim, or during circular sewing—the risk of skipped stitches increases, partly due to needle deflection. Schmetz and other needle manufacturers offer special needles designed to prevent such problems (e.g., SERV 7 by Schmetz).

Avoiding skipped stitches
The problem of skipped stitches often occurs with extremely elastic fabrics, with layers of varying thickness, and with cross-stitching. With extremely elastic fabrics—such as those used for swimwear, bras, bodysuits, etc.—the material tends to flutter due to the moving needle. With materials of varying thicknesses, the risk of skipped stitches increases, partly due to needle deflection. Needle manufacturers offer special needles for this purpose, such as the “SERV 7” from Schmetz. The SERV 7 features a ridge in the groove area and additional shaft reinforcement. The ridge helps form the thread loop more effectively, thereby preventing skipped stitches. The shaft reinforcement provides greater stability to the entire needle, which significantly reduces deflection.

Needle Tip—The Right Tip for Every Fabric
We generally distinguish between ball points, which pierce through the loops of woven fabrics, and cutting points for leather and films, which pierce the material by cutting through it.

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 dictates the needle system. Then choose the most suitable tip shape and the gauge that best matches your thread.

Good luck and have fun sewing!