Leather Needle Sizes

Picking the right needle for hand-sewing leather can be the difference between a 30-minute job and an hour. If your sewing needles are ill-suited to your work, you will fight through every stitch on your project. If you pick the right combination of needle and thread, sewing can be the most relaxing part of your work. Many articles talk about the types of sewing needles like glovers, lacing, and curved needles, but 95% of the time, you’ll be using harness needles. Today, I’ll go over what makes these needles ideal, how to use them, and when to use different needles.

To clarify, I’ll be discussing hand-sewing needles today. Machine sewing needles for leather is a whole topic unto itself.

Suit the Needle to the Thread, the Thread to the Needle

The purpose of using needles is to push your thread through the leather, plain and simple. I often get the question, “What size needle do I use for leather?” the easy answer is nearly the same size as your thread. If your thread is 1mm thick, your needles should be a bit less than 1mm. You don’t want your needles to be much thicker than your thread because you’ll have a hard time pushing the needle through your stitch holes. On the back stitch, where there is already a thread in the hole, you’ll have an even worse time with too thick needles. Your needles shouldn’t be too thin relative to your thread, either. Overly thin needles will more easily pierce thicker thread and you’ll have to spend time fixing it.

Some threads are quite loose in their twists; you can unravel them with little effort. In these cases, I’ll size down the needle by one because the thread compresses when I pull it through the stitch holes. Lastly, remember that what passes through the stitch hole isn’t just the needle; it’s the needle plus the two widths’ worth of thread. This is because the thread passes through the eye, so it’s a thread on one side, the needle, and more thread on the other. So, an MBT #8 Polyester thread in a size four needle has an approximate width of 1.92mm.

Leather Hand-Sewing Needle Chart

What size needle for 1mm thread in leather? 0.8mm? Size 8? I made a handy chart of the John James Harness Needles that we carry, paired with the different threads we carry:

Needle Size	Needle Diameter	Linen Thread	MBT Polyester	TEX	Thread Diameter
4	0.86mm	632 – 832	#5 – #20	<125	< 0.6mm
2	1.02mm	332 – 532	#1 – #5	<150	< 0.9mm
1/0	1.09mm	332 also	#1 also	<277	< 1.1mm
2/0	1.42mm		#0	<410	< 1.25mm
3/0	1.63mm		#00	>411	>1.25mm

To Be Blunt

If you are hand-sewing leather and pre-punching your stitch holes or are using an awl while sewing, your holes are already accounted for. You use blunt or round point needles instead of sharp-tipped ones. With sharp needles, you can more easily pierce your thread. You also increase the chance of making new holes. We’ve all been in a situation where our holes are misaligned, and the needle isn’t going through the leather. Most new students will try to brute force their way through the hole. If you use sharp needles, you end up piercing new holes, and your stitch spoils. If you are using blunt needles, then you are forced to use the right technique: rotate your needles until you find the holes you already made with your irons or awl. Blunt tips don’t make new holes, which is critical to making nice-looking stitches.

Glovers Needles

There are other types of needles for leatherworking. Many leathercrafters rarely use these needles, so I’ll briefly highlight their uses.

Glovers needles are called such because glovers traditionally used them. The tips are sharp and triangular-shaped, so they are meant to pierce the leather without tearing a larger hole. Glove leather is usually soft, thin, and sometimes fur-lined on the inside. I’m not trained as a glove-maker, but if I were to hand-sew portions of a glove, I’d probably want a very small stitch hole. I imagine your leather would not be pre-punched. If it is fur-lined, you’d never find the holes anyway. The small triangle points would be ideal for this, where you make fine holes in thin leather. I’ve seen them referenced in older books, like in Al Stohlman’s sewing book, when using wool-lined leather. If anyone is trained as a glover, I’d love to learn more about glovers needles.

Bonus: How to curve your needles

I found that the pre-curved needles you can buy are a bit too circular for doing a butt seam. I want a slight curve to angle from the face towards the edge but not point the end upwards. I remembered the old Al Stohlman book has a section on curving your needles by simply heating them. I tried this out and did a short video:

To sum up, what is the best needle for stitching leather? It matches your thread and doesn’t make new holes. Suit the needle to the thread, the thread to the needle, and your needles will always be right.