A Thread About Thread

[kc7fys]

I'm not seeing a thread thread here that answers these questions:

How are thread thicknesses graded? I used Gutermann's 70 black from Arrowhead for my first projects. Is that the only type used here?

What about using one heaviness in the bobbin and another up top?

Thanks,
Jonathan

[jred]

I can't imagine why you'd want to use a different thread top & bottom. It'll only be as strong as the weakest thread. Plus, I'm pretty sure I read a thread that said it'll cause issues, loops & tangles & whatnot.

[Ramblinrev]

IMO... normal household thread is sufficient for all DIY projects. Some folks use a different thickness for different purposes. This falls into the realm of personal preference. I would not use two different types of thread in the spool and bobbin unless you were looking for a specific effect. EG: you are making a reversible underquilt and you want to match the thread to each side. Different thickness thread might lead to some interesting visual effects but unless someone is going to look at it very closely I don't think it would make much sense to do. The tension adjustments needed would be too cumbersome to make the effect worthwhile in my opinion. YMMV.

[Spock]

I agree with Ramblinrev. Stick to one thread top and bottom. I have used Gutterman's successfully for years for almost everything. It is available from most fabric stores and owfinc.com. Occasionally, I'll use nylon upholstery thread, but only on heavy fabric.

[nacra533]

If I recall correctly, thread is actually graded in tensile strength instead of thickness and some systems grade it on retained tensile strength after xx hours of weathering for outdoor thread. Since similar yarns are used to make varying threads, thickness kind of becomes the judge of the thread weight. ex. polyester is polyester, and it's tensile strength is known, so a 46 weight thread by lots of manufacturers will have the same thickness. Most household threads are "spun" which gives the appearance of varying thickness between spools and sometimes on the same spool. "Smooth" thread is smooth and much more consistent in diameter. It does not sew as well as the spun thread (frequent tension adjustments) but it is generally a little stronger and consistent in it's strength. Manufacturers add a coating to make it sew throught the tension disks and needle eye to some threads and it is called "bonded thread."

It is rare to see the thread size printed on the label of household thread but it is very common to see it on industrial spools. Coats and Clark has an bad habit of putting something that looks like thread size on some of their threads, like T27, but it's their product number and has nothing to do with thread size (except in the "outdoor" thread line, which is labled T70 and is Textile 70 siz bonded polyester. I don't recommend Coats brand from sewing stores or big boxes. Their industrial threads on larger cones are OK.

To add confusion, there are a lot of different "systems" by which to measure thread. Goretex / Tenera threads have added to the confusion because they retain strength much longer and don't have a "typical" size. Since the smaller threads lose very little strength, folks use 1 or 2 sizes smaller than they traditionally would for outdoor / marine products.

The most common thread size for gear making is about a 46 weight thread, sometimes on larger spools, it will indicate Ticket size 70, which is not Textile size 70.

V46=Textile 45= Ticket 70= Govt B = 7# tensile strength for bonded poly
V69 = Textile 70 = Gov't E size = about 10# tensile strength for bonded poly

Sorry, did you ask what time it was or how to build a watch?

[sclittlefield]

How are thread thicknesses graded? I used Gutermann's 70 black from Arrowhead for my first projects. Is that the only type used here?

Gutermann Mara 70 is Tex 40. (Nearly) All thread measurements are based on weight, not diameter / size. And there are so stinkin' many measurement methods that it's ridiculously confusing. Some brands use one, others use another, and so on. Tex is, in my opinion, the most useful designation for comparing thread.

The Tex system is based on the weight in grams of a thread 1 kilometer long. A kilometer of tex 10 (very fine) thread weighs 10 grams, while a kilometer of tex 100 (very coarse) weighs 100 grams. The Tex system measures the entire thread, no matter how many strands or plies it has. While a thread can have any actual weight, the Tex system has official ranges of sizes that get the same Tex number. For example, all threads weighing between 24.0 and 26.9 grams per kilometer are designated T-24. LINK

Tex 40 Polyester thread is about the most common used among DIY and Cottage Industry guys and gals here at HF. Gutermann Mara 70 being the most common brand among them all (the style found at OWF, Arrowhead, Backwoods Daydreamer... etc.). This "size" works well on all home and industrial sewing machines and is strong enough for most applications.

And for your reading pleasure: "A Thread of Truth" (About the best short writeup on thread I've seen recently)

[waddy]

I'm not seeing a thread thread here that answers these questions:

What about using one heaviness in the bobbin and another up top?

Thanks,
Jonathan

The heavier industrial stitchers like I use to stitch leather do recommend a size lighter thread in the bobbin than on top. That may be where you have heard that. As the thread size decreases, they all recommend the same size top and bottom. Hope that helps.

[kc7fys]

Understood. It messes with thread tension, too--having two weights of thread in play. It just happened the other day when I had a bobbinful of lighter grey and some gutermann's black up top. Thank you for the excellent explication on thread!

[exup]

Speaking to a friend of a friend who owns a thread inector repair shop told me the home machines are not designed to use thicker than average threads. Only problems will occur, which in the long run may make the item weaker.

I used some 100% polyester clear thread from michaels that was about as thick as 6lb test fishing line and the machine was not having it and it left weak spots sewn incorrectly.

I've had the same questions recently so were pretty much in the same boat.