Sewing machine needles are important. Picking the correct one for what you are sewing will make all the difference in your sewing experiencing. An ill-matched needle can cause headache and frustration.
There are two main things to consider when picking the needle to sew with. In this article we are going to look at size only. (The other thing is needle type.)
Many sewing machine manuals will give guidance in them regarding needle sizes for the fabric you are sewing.
They generally give a table and it goes something like this: small needles are used for light fabrics and large needles are used for heavy weight fabrics.
And while that is mostly true, there are some times when maybe it isn’t.
First, of all, the size of needle refers to the diameter of the needle blade. The length of the needle is fairly standard. There are different lengths depending on the style or kind (system) you choose. But most sewing machines take a standard HAx130 “system” needle. And these come in different types for different kinds of fabric (stretch, woven, leather etc).
But all of them tend to come in a range of sizes. The smallest I’ve seen is a size 8 and the largest a size 20. You may also see these sized 60 to 120. Where a 60 corresponds with size 8, 70 with size 10, 75 with size 11, 80 with 12, and so on.
In all cases, the larger the number, the larger the needle.
So, what to consider when picking the size of needle? There are 4 main things:
Fabric weight, fabric density, fabric type and thread size.
It’s true, in general, light weight fabrics need smaller needles. Heavier weight fabrics need larger needles. But, this is a generality.
So, yes, if you are sewing chiffon, a smaller needle (8-10) will be a good place to start.
If you are sewing pant-weight twill, a larger needle like 12 may be a good place to start.
Heavier upholstery fabric may benefit from an even larger needle like size 14 or 16.
Weight isn’t the only thing to consider though.
The density of the fabric can play a role in the choice of needle as well. Density being how close together the threads are in the weave or knit. More dense fabric will have more threads per square inch of fabric.
In my experience, more dense fabric benefits from sizing down.
For example, I frequently sew with an upholstery weight faux sued fabric, and it’s quite dense. And while most of the upholstery weight fabrics I’ve sewn do fine with a size 14 or 16, this particular fabric prefers a 10 or maybe 12 if I’m not sewing too many layers.
One way I tell if the fabric needs a different needle is if I can see or hear the machine struggle when trying to sew. When the machine is struggling, my machine will often sound louder, or make a more thunking sound as the needle goes through.
And yes, sometimes I need to keep the same size but change the type (like to a leather or denim needle). But often picking a smaller needle really helps.
But, caution: smaller needles will be at higher risk of breaking or bending if they can’t go through the layers of fabric.
Why does density really matter? Well, the needle needs to be able to pierce through the fabric. But it needs to be able to do this in time to have the thread grabbed by the hook of the sewing machine in order to make a stitch.
If the needle is delayed, the timing might be slightly off and a stitch won’t form. You’ll see skipped stitches.
The type of fabric can matter regarding size.
For example, faux leathers are really vinyl coated fabric. And the coating of the vinyl doesn’t “recover” from being punctured by a needle unlike uncoated fabric. So, a smaller needle will leave a smaller hole. And this can be desirable.
Also, some shiny fabrics like satin snag a little more with larger needles so a smaller needle is often preferred.
While it’s not always obvious, there are different sizes of thread.
And, the larger the needle, the bigger the hole (or the eye of the needle) is for the thread (usually).
There are needles that have larger holes on purpose. That is more of a needle “type”. But that’s to allow larger thread to pass through.
The risk of using a needle with too small of a hole with a larger thread is that the thread could rub too much in the hole and eventually break.
The standard needle eye size works with all-purpose thread.
However, if you want to sew with embroidery, upholstery, or metallic thread, consider the needle hole size. Size up if you can, or use a needle with a specifically larger hole for this kind of thread.
This is true, too, if you want to use two threads on top. It’s doable, but you may need to get a double-eye needle, a larger hole needle, or size up.
So, to choose your needle size, first consider the fabric weight, then the density. The type of fabric may play a role for reducing the marring of the fabric surface. And if you see issues with your thread, it could be the needle.
Size does matter. But bigger isn’t always better.
Sometimes sizing down makes a huge difference.
When I sew, I use between size 10 and 12. I rarely go above 12, or below 10. I find size 8 needles really hard to thread. And I rarely use anything above a 14. In fact, I rarely use size 14.
I more often find myself switching needle types. Learn more about needle type and fabric pairing in my article “Machine Needle Type and Fabric Pairing”.
And as always, a new undamaged needle will behave better and give better results than a worn out or damaged needle. The wear or damage is not always visible to the naked eye.