Sewing Machine Needle Size

Definition and Overview

The size of a sewing machine needle is the reference number used to distinguish needle thickness, whether for household or industrial use. In general, the larger the number, the thicker the needle shaft becomes, making it better suited to thick fabrics and high-density textiles.

The size is information indicating the dimensions of the needle itself, and it is different from the sewing thread size used to indicate thread thickness. It must be checked together with the needle type, needle point shape, and needle mounting standard.

How Thickness Is Expressed and How It Differs from Thread Size

Sewing machine needles indicate thickness by gauge or number. Even with the same size, the shaft shape, length, and groove differ depending on the type of sewing machine used, so compatibility cannot be determined by size alone.

Sewing thread size is an indication of thread thickness, and generally the larger the number, the finer the thread. On the other hand, sewing machine needles generally become thicker as the number increases, so the numerical relationship tends to be reversed, and care is needed to avoid confusion.

• Needle size: A reference number indicating the thickness of the needle shaft.
• Sewing thread size: An indication of thread thickness.
• Needle mounting standard: The needle type that determines which sewing machines can use it.
• Needle point shape: A shape related to suitability for materials, such as for woven fabrics or knit fabrics.

How to Choose and Sewing Precautions

Needles are selected based on a combination of not only fabric thickness, but also weave density, knit structure, presence or absence of coating, stretch, and sewing thread thickness. Thin needles are often used for lightweight fabrics, and thick needles for heavy fabrics and overlapping seams, but it is important to confirm through sample stitching.

A needle that is too thin can cause needle breakage or skipped stitches, while one that is too thick can make the needle hole stand out, cause thread breakage, or lead to puckering. For knits and stretch materials, the needle point shape, such as a ball point, is also matched to the material.

Before sewing, check the appearance of the stitches, seam shrinkage, seam strength, and how the needle holes remain using the specified thread. In continuous sewing, needle wear and bending also affect quality, so replacement should be managed according to process conditions even if there is no abnormality.

Main Applications

Fine-gauge needles are used when sewing lightweight materials such as lawn, chiffon, and lining with the needle holes kept as inconspicuous as possible. For medium-weight fabrics, they are selected to match shirt fabrics and general apparel fabrics, while balancing the thread and textile.

Thick-gauge needles are used for heavy fabrics such as denim, canvas, and duck cloth, high-density woven fabrics, and processes involving multiple layers. However, depending on the material, even a thick needle may not have sufficient penetration, so sewing machine conditions and needle point shape also need to be adjusted.

Differences from Similar Terms

A sewing machine needle refers to the entire needle attached to the sewing machine, and the size of a sewing machine needle is the specification related to its thickness. The needle eye is the hole in the needle through which the thread passes, and when the needle size changes, the size of the needle eye also affects compatibility with the thread being used.

Normal point and ball point are classifications of needle point shape. Even with the same size, a sharp needle point is selected for woven fabrics, while a rounded needle point that is less likely to damage the yarn in knit fabrics is selected for knits, depending on the material.

Frequently Asked Questions