Thread Size Perspective?

[Colt W Knight]

Does anyone have any good pictures that puts sewing machine thread into perspective? I am new to leather and sewing, so I don't have a good handle on how big/small different thread sizes are.

[Wizcrafts]

I don't have photos handy right now, but I can put leather thread sizes into perspective compared to home sewing thread.

Most home sewing machines are built to use the cotton or polycore threads sold at Walmart, Kmart, Target, Joann Fabrics, etc. The typical number equivalent that makes sense to us would be that those common domestic sewing threads for shirts would be about 1/2 to 2/3 the thickness of the smallest thread commonly used in leather sewing: #b69, or Tex70. The domestic thread would require a #11 or 12 needle. The smallest thread we use (69) requires a #16 or 18 needle.

Strength-wise, domestic cotton thread might break with a good tug of your hands, pulling the ends of the thread in opposite directions. #69 bonded nylon requires 11 pounds pull before it thinks of breaking.

Jeans are usually sewn with what's sold as Jeans thread. It can be had in three sizes, from super thin to quite thick, with #80 being the most common. This is a topstitch thread that is hard to sew on a domestic machine. It requires a #19 needle, at minimum. Domestic needles normally stop at #18. The next size to it in bonded thread is #92 (T90). It has 50% more strength than #69 and requires a #19 or 20 needle. This is a good size for wallets, purses, backpacks and lined belts not exceeding 6 - 8 ounces thickness.

Serious leather sewing begins with #138 bonded thread, using a #23 leather point needle. The breaking strength is 22 pounds pull. I use it to construct rifle slings, guitar straps, pocket holsters, heavier wallets and money belts. Domestic machines cannot sew with this thread under any circumstances. This is also the largest typical thread used in upholstery and in upholstery class walking foot machines.

Holsters, double leather belts, knife sheathes, handcuff pouches and the like are usually sewn with combinations of #207 and #277 bonded thread. Items that are subject to abuse, or which must not give up the thread if the item gets caught in something, or holsters that could be in life and death struggles for a gun, should be sewn with a minimum of #277 thread, top and bottom. This thread has 44 pounds strength per stitch. It requires a #25 leather point needle and a very large and super heavy duty sewing machine. These machines are sometimes called harness stitchers. Many here use what we call 441 clones, based on the original Juki TSC-441, but half the cost.

Saddlers and harness makers from the old school often prefer a different stitching machine than the 441 types, which are triple feed walking foot machines, using a large, closed eye needle. They often own needle and awl stitchers, which use a barbed eye needle and stabbing awl. The machines are HUGE and heavy; sometimes being over 100 years old and still going. I've owned two of these: Union Lockstitch machines. They didn't blink when sewing with #346 and larger thread, which has a 66 pound strength per stitch. I even used #554 at times, which is almost 1 mm thick. I used #346 thread on double leather weight lifters' belts, sewn on a Union Lockstitch machine. With the pedal all the way down, they sew 15 stitches per second and sound like 50 caliber machine guns.

I hope this helps put threads into the perspective you were seeking.

[Colt W Knight]

Thanks Wiz. You are a tremendous help. I have contacted several of the vendors on this forum about buying a new machine, and I now I have to figure out if I want the 3200 or the full size class 4/4500 machine. Plus, who do I order from? Neel, Bob, and Steve were helpful and answered a bunch of my questions. Seams like they were all within 50$ of each other price wise.

[Wizcrafts]

... Plus, who do I order from? Neel, Bob, and Steve were helpful and answered a bunch of my questions. Seams like they were all within 50$ of each other price wise.

I have bought stuff from all of the above. No regrets. I now get most of my machines from Toledo Industrial, which is just 114 miles south of me. You are quite a distance away from most of our member dealer, so you will be paying a shipping charge. A difference of $50 shouldn't be the most important option when buying a new sewing machine.

Talk to these dealers and let them know where you are at as a sewer. If you are at the beginner's stage, they can anticipate having to answer a lot of follow-up questions. Can you wait for replies to voicemail messages you leave? Or, will you require instant answers? Will email exchanges work for you? These are important questions only you can answer. The people running these businesses are often very busy picking up, setting up, servicing, or delivering machines. They will all call you back, but it may not be instantly, or even the same day. I sometimes have to use email or private messages through the forum to get answers to minute detail questions I have about this or that machine.

Sometimes you can get help faster from other members who own the same machine you are having problems with.

Regarding the CB3200 vs the CB4500/Class 4, decide first how thick you will need to sew once your business is in full swing. Also, try to anticipate how long the arm should be to clear the work you may have to sew. I have a 4500 which has a 16.5 inch arm and need every bit of it on some jobs. My previous harness stitcher had 12" clearance and that was often inadequate.

Bear in mind that a long arm may also come in handy for thick leather items that need to be turned around as you sew them. If the body depth is too short, the item will have to be bent up or down as you turn it. That may not always be possible. A longer arm will save the job.

[Colt W Knight]

Basically, I am not in the leather business. I am scientist by trade, and projects like leather or guitar building, are a very serious hobby. I do sell some projects, but most of what I make are gifts or fabricating things I use because I like to make stuff.

In the immediate future, I have no need for the bigger machine. However, in the future I can see myself repairing horse blankets and even making a saddle or two. A lesson I learned wood working is that if I buy a machine bigger than I think I need, I can find a use for the expanded capacity. The more I think out loud, the more I am leaning towards the big machine.

[Wizcrafts]

Consider this scientific fact: A CB4500 can sew everything that a CB3200 can sew. This includes the thickness of the leather, depth to the right and thickness of the thread. It does these things when you are only sewing 1/2 inch or under. Both machines will sew 8 ounce projects with #138 thread. Both will lay down a tight stitch of #277 into 1/2 inch of holster or sheath.

That is where the comparison ends. The CB4500 will continue to sew thicker packages and wider projects. It will accept a raised holster or stirrup plate and still have enough top clearance to sew 3/8 inch of leather on the plate. The 3200 cannot do that.