Thread Types And Uses? Leather Types And Uses?

[Nessmuk1]

Wondering what types of threads are used in machine leather sewing, and what ones are used in what type leathers?

Also wondering about the types of leathers used, and if different needle sizes are used for different leathers?

Direction toward a good book would or source of info in chart form would be great.

[TwinOaks]

Look at the advertisers at the top of the page - those that are sewing machine dealers often include some of that basic information.

General info: We typically use 3 types of common thread, cotton/linen, polyester, and nylon. There is also 'Artificial Sinew' (which is nylon), and it is used in some applications that are to appear 'period correct'.

You can use any thread in any leather, but sometimes it's preferred to use one over another. Linen has the longest historical use for just about all applications and can still be found in things that use chain stitching. Linen is used because it's easy to wax the thread with a liquid acrylic wax which locks the stitches in place once it dries. Redwing shoes/boots use this method for sewing the upppers. Nylon is often found where strength and durability are a concern, specifically Bonded Nylon - saddles, holsters, sheaths, hard use items....long list! Polyester (aka Poly) is also used in those things but may also be found in purses, bags, wallets, et al., because it can have a softer feel to it - referred to as 'the hand' of the thread. I.e. a soft thread to the touch is said to have a soft hand.

The size of the thread is dictated by the size of the thing being sewn. You wouldn't use really thick thread for something like a wallet liner, nor really thin thread for a saddle. This is partly for aesthetic reasons, partly for the physics of sewing. Just about all machines use a lock stitch (some use a chain stitch). A lock stitch is two threads entering and exiting a stitch hole and crossing each other once, just like hooking your fingers together. That place where they cross each other is often referred to as the knot. For the stitch to look good and actually be 'locked', the knot needs to be between the pieces that are being sewn together. If you have very thin material, it becomes difficult or impossible to keep the knot between the layers, which results in the thread not being locked in place, and possibly slipping. For example: Using thread that was thicker than either of the two pieces being sewn would result in the knot resting on either the top or the bottom of the sewn piece, as it can not physically fit between the two smaller pieces.

On the opposite side of the spectrum is sewing thick material with thin thread. To have any significant strength, there would need to be MORE stitches because the thin thread isn't as strong as thick thread. This creates a problem with sewing leather because if the stitch holes are too close together, you end up perforating the leather just like a paper towel.

So, you end up with thick material requires thick thread, thin material gets thin thread. There are exceptions, but I did preface this with "general information".

[Nessmuk1]

Thank you. I've heard of Tiger thread and others, are they different?

[TwinOaks]

I haven't used it, but the brand has a good following on here (and elsewhere) and the reports say that it's a good thread.

[JLSleather]

Oh, and then there's Kevlar thread, which is exactly what you think it is. Zero stretch and a breaking strength about 2 1/2 times that of nylon or poly thread (for same diameter). Much more costly, and largely prohibitive for leather craft. If, on the other hand, you are sewing parachute harness ...