Bluesman Report post Posted March 2, 2014 (edited) In anticipation of my new machine many things race through my head. I've found the various thread to needle size charts but am still wondering if there is a 'Rule of Thumb" you stitchers use when using varying leather wights. I bought a Cobra 4 and it will do 6 oz to 7/8" of leather. I will be getting several spools, of different colors in both 207 and 277 along with #23, #24 and #25 leather point needles. Now for the question. Is there a chart or something in somebody's head that could fill in the blank? Leather project OZ - ????? Recommended Needle - ???? Recommended thread - ????? Recommended SPI - ???? I understand that experimentation is the key however just looking for some guidelines to start with. For example. I want to do a project composed of a 4/5 oz top, 2/3 oz liner and another 2/3 oz pocket. So the total project is about 8 - 11 oz total. What needle/thread and SPI would you start with? Part of the project will just be the 4/5 oz top and the 2/3 oz liner. But I want to stitch it complete so the total weight will vary as I stitch along. Thanks in advance, Jon Edited March 2, 2014 by Bluesman Quote Share this post Link to post Share on other sites
JLSleather Report post Posted March 2, 2014 (edited) Leather Recommended Needle Recommended thread SPI - ???? I understand that experimentation is the key however just looking for some guidelines to start with. For example. I want to do a project composed of a 4/5 oz top, 2/3 oz liner and another 2/3 oz pocket. So the total project is about 8 - 11 oz total. What needle/thread and SPI would you start with? Part of the project will just be the 4/5 oz top and the 2/3 oz liner. But I want to stitch it complete so the total weight will vary as I stitch along. Jon That's a LOT of questions I think I tend to run about one notch lighter than lots of folks when it comes to thread size. Some of that stuff is maybe better for pulling your truck outta the snow bank than for stitchin So your specific project ... think i'd probably wanna use a #138 thread at about 6/7 spi. There's some 'flex' in that depending on how firm the leather is, and such. Depending on where the pocket "hits", I might use up to 8spi. I rarely do anything 'tighter" than that. For gun slings / guitar straps, same thread and maybe step it up to 6 spi (largely decorative anyway). heavier stuff, heavier answer - so, holsters 207, weightlifing belts 207 or 277 @ 5 spi (that much strength isn't necessary - only in the mind of the weightlifter). I personally use thread down to a #46 (as well as 69 and 92) but that's under what your machine wants to do, no? Edited March 2, 2014 by JLSleather Quote Share this post Link to post Share on other sites
Bluesman Report post Posted March 2, 2014 JL thanks just what I'm looking for, guidelines and opinions. yes the Cobra goes down to a 138 thread. Actually not a lot of questions just trying to put together a recipe so when I want to do something I have at least a starting point. Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 2, 2014 (edited) I try to match the size and breaking strength of the thread to the project. Plus, one has to choose a combination that conceals the lockstitch knots between the layers. So, here are some of my general recommendations for you. For very thin and/or soft projects, 3 - 5 ounces: #69 thread with a #18 needle (below 441 practical limit. Round point only.) (8 /inch) For thin projects, 6 - 8 ounces: #92 thread with a #19 or #20 needle (at practical bottom 441 limit. Round point only.) (7 /inch) For 9 - 12 ounces: #138 thread with a #23 needle (typical, consistent 441 bottom limit. Smallest leather point 794 needle) (6 /inch) For 13 - 20 ounces: #207 thread with a #24 needle (great for stitched belts, single and double leather) (5.5 /inch) For 21 - 28 ounces: #277 thread with a #25 needle (5 /inch) For 1/2" to 3/4": #346 thread with a #26 needle (4 /inch) Extra heavily stressed projects, 3/4" to 7/8": #415 thread, with a #27 needle. (3.5 to 4 /inch) Exceptions Holsters, outside the pants, with security thumb-breaks: If at least 1/4 inch thick, use #277 thread, at 5 /inch. The knots can be buried inside the layers and the 44 pound thread breaking strength resists tearing during a struggle for the gun. Sam Browne duty belts, 1/4" to 5/16" should be sewn with #277 thread, at 5 /inch. Extra thick, double leather (over 3/8") professional weight lifter's belts should be double row stitched with #346 thread, at about 3.5 or 4 to the inch. These belts take a tremendous amount of stretching and abuse. Stitches per inch I use long enough stitches to look good on top without forming loops on the top or bottom when the project is bent (like a belt). Conversely, when the work calls for closer stitches, you have to make sure they don't perforate the stitch line. Why? "S" point needles, like the type 974 Schmetz makes for 441 clones, slice the leather with inline, wedge shaped cuts. This buries the ends of the thread inside the top grain and makes it appear like the stitches are closer together. If properly spaced, thick thread adds to the strength of the package. But, if placed too close, the holes in the leather weaken the package beyond the thread's ability to secure it. In fact, if the holes are so close that the thread is stronger than the leather between the holes, it can slice right through them. Also, the larger the diameter of the thread, the bigger the knots formed by the lockstitches. When sewing with thick thread, like 207 and larger, space your stitches out to avoid slicing through the leather: e.g., no smaller than 6 to the inch. When sewing with #138 thread & 23 needle, you can go a little shorter, to 7/inch. If you use #69 or 92 thread, 8 to the inch is okay. Thread breaking strength list #69 (T70): 11 pounds #92 (T90): ~16 pounds #138 (T135): 22 pounds #207 (T210): 32 pounds #277 (T270): 45 pounds #346 (T350): 53 pounds #415 (T400): 72 pounds Edited March 2, 2014 by Wizcrafts Quote Share this post Link to post Share on other sites
Bluesman Report post Posted March 2, 2014 Thanks Wiz....excellent primer. Just what I'm looking for. Quote Share this post Link to post Share on other sites
BigJake Report post Posted March 3, 2014 I try to match the size and breaking strength of the thread to the project. Plus, one has to choose a combination that conceals the lockstitch knots between the layers. So, here are some of my general recommendations for you. For very thin and/or soft projects, 3 - 5 ounces: #69 thread with a #18 needle (below 441 practical limit. Round point only.) (8 /inch) For thin projects, 6 - 8 ounces: #92 thread with a #19 or #20 needle (at practical bottom 441 limit. Round point only.) (7 /inch) For 9 - 12 ounces: #138 thread with a #23 needle (typical, consistent 441 bottom limit. Smallest leather point 794 needle) (6 /inch) For 13 - 20 ounces: #207 thread with a #24 needle (great for stitched belts, single and double leather) (5.5 /inch) For 21 - 28 ounces: #277 thread with a #25 needle (5 /inch) For 1/2" to 3/4": #346 thread with a #26 needle (4 /inch) Extra heavily stressed projects, 3/4" to 7/8": #415 thread, with a #27 needle. (3.5 to 4 /inch) Exceptions Holsters, outside the pants, with security thumb-breaks: If at least 1/4 inch thick, use #277 thread, at 5 /inch. The knots can be buried inside the layers and the 44 pound thread breaking strength resists tearing during a struggle for the gun. Sam Browne duty belts, 1/4" to 5/16" should be sewn with #277 thread, at 5 /inch. Extra thick, double leather (over 3/8") professional weight lifter's belts should be double row stitched with #346 thread, at about 3.5 or 4 to the inch. These belts take a tremendous amount of stretching and abuse. Stitches per inch I use long enough stitches to look good on top without forming loops on the top or bottom when the project is bent (like a belt). Conversely, when the work calls for closer stitches, you have to make sure they don't perforate the stitch line. Why? "S" point needles, like the type 974 Schmetz makes for 441 clones, slice the leather with inline, wedge shaped cuts. This buries the ends of the thread inside the top grain and makes it appear like the stitches are closer together. If properly spaced, thick thread adds to the strength of the package. But, if placed too close, the holes in the leather weaken the package beyond the thread's ability to secure it. In fact, if the holes are so close that the thread is stronger than the leather between the holes, it can slice right through them. Also, the larger the diameter of the thread, the bigger the knots formed by the lockstitches. When sewing with thick thread, like 207 and larger, space your stitches out to avoid slicing through the leather: e.g., no smaller than 6 to the inch. When sewing with #138 thread & 23 needle, you can go a little shorter, to 7/inch. If you use #69 or 92 thread, 8 to the inch is okay. Thread breaking strength list #69 (T70): 11 pounds #92 (T90): ~16 pounds #138 (T135): 22 pounds #207 (T210): 32 pounds #277 (T270): 45 pounds #346 (T350): 53 pounds #415 (T400): 72 pounds Wiz, Great post and very useful info......thanks! Quote Share this post Link to post Share on other sites
BDAZ Report post Posted March 3, 2014 Wiz, that response should be a sticky.. Cya! Bob Quote Share this post Link to post Share on other sites
JLSleather Report post Posted March 3, 2014 Wiz, that response should be a sticky.. Cya! Bob I MEAN it ... Primer? That's a whole CLASS Quote Share this post Link to post Share on other sites
Bluesman Report post Posted March 3, 2014 Well as long as this may be a sticky. how about this. Which direction does the needle thread come off the spool? If I pull it from the back the spool turns clockwise. If pulled from the front the spool turns counter clockwise. i'm asking because I've read the comment "left" and "right" hand wrap. How does this enter into the equation. The thread I will be using is coming from Cobra. Quote Share this post Link to post Share on other sites
Northmount Report post Posted March 3, 2014 Well as long as this may be a sticky. how about this. Which direction does the needle thread come off the spool? If I pull it from the back the spool turns clockwise. If pulled from the front the spool turns counter clockwise. i'm asking because I've read the comment "left" and "right" hand wrap. How does this enter into the equation. The thread I will be using is coming from Cobra. If you are using the 1/2# or 1# spools, the thread comes vertically off the top of the spool. You will have a spool stand that holds usually 2 spools. The spools don't rotate. Take a look at the web photos of your machine or a number of videos that are out there. Tom Quote Share this post Link to post Share on other sites
dirtclod Report post Posted March 3, 2014 Your machine will come with a thread stand. The thread sets on it and goes straight up then over to your machine so you spool should never turn or need to turn. Quote Share this post Link to post Share on other sites
Bluesman Report post Posted March 3, 2014 Thanks folks. I love to over-think the obvious. Quote Share this post Link to post Share on other sites
AftonCraft Report post Posted March 14, 2014 I just purchased a second-hand Consew 206RB-5 in great shape, and Wizcraft's guidance on thread, needles, and SPI is a perfect list to get me started on making the prototype of a combination woman's handbag and bicycle saddlebag. Quote Share this post Link to post Share on other sites
Cole Report post Posted March 14, 2014 Wizcraft does your recommendations work with all machines? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 14, 2014 Well as long as this may be a sticky. how about this. Which direction does the needle thread come off the spool? If I pull it from the back the spool turns clockwise. If pulled from the front the spool turns counter clockwise. i'm asking because I've read the comment "left" and "right" hand wrap. How does this enter into the equation. The thread I will be using is coming from Cobra. The left or right hand twist (or wrap) we refer to is the direction in which the cords of thread are twisted together. If you hold a section of thread between both thumbs and index fingers, then twist down, away from you with the left fingers, counterclockwise, the thread will tighten. This is the standard sewing thread direction of twist or wrap.for most lockstitch sewing machines. It is also known a Z twist. The way the hooks work on modern machines, left twist stays together or gets tighter in operation. Reverse, or right twist thread is wound the other direction and tends to unravel in most lockstitch machines. Shoe sole stitchers use right twist thread. Some hand sewing waxed thread is wound with a right twist. Double needle machines have vertical axis hooks. If one hook rotates in the opposite direction to normal, right twist thread will not tend to unwind like left twist might. Wizcraft does your recommendations work with all machines? No, only on sewing machines. Quote Share this post Link to post Share on other sites
Cole Report post Posted March 14, 2014 Gotcha.. Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 14, 2014 Gotcha.. Sorry, but I couldn't resist! ;-) My advice works for most leather capable sewing machines. The smallest needle/thread combination in my list is usually the maximum size for a home sewing machine. Old iron body machines can probably handle up to #92 thread, if you can find #19 or 20 needles to fit them. Most upholstery grade walking foot machines can sew up to 3/8 inches, with a #23 needle and #138 thread. Sewing thicker, material, or using bigger thread usually means stepping up to the largest machines. Quote Share this post Link to post Share on other sites
Bluesman Report post Posted March 14, 2014 I have condensed this thread down to the specific comments that make for a useful document. I have it here for all to download as a PDF. Thanks for all the input. Sewing Machine Guidelines for Leather, Thread and SPI.pdf Sewing Machine Guidelines for Leather, Thread and SPI.pdf Quote Share this post Link to post Share on other sites
Cole Report post Posted March 15, 2014 Wizcraft is the artisan 618-1sc considered a 441 clone? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 15, 2014 (edited) Wizcraft is the artisan 618-1sc considered a 441 clone? No, it's just a standard upholstery grade machine. Examples of 441 clones sold by our member-dealers include: Cowboy CB3200, CB3500 and 4500 Cobra Class 3 and Class 4 Techsew 4100 and 5100 The actual 441 is the Juki TSC-441 Edited March 15, 2014 by Wizcrafts Quote Share this post Link to post Share on other sites
Cole Report post Posted March 15, 2014 Will the artisan be good for making wallets? Will the artisan be good for making wallets? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 15, 2014 Will the artisan be good for making wallets? Will the artisan be good for making wallets? Yes Yes Quote Share this post Link to post Share on other sites
Cole Report post Posted March 16, 2014 Is the artisan good for both thick and thin leather Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 16, 2014 Is the artisan good for both thick and thin leather If by thick, you mean 3/8 inches, yes and with up to #138 bonded thread and a #23 needle. It can sew down to probably 2 ounces of firm leather, using #46 bonded thread and a # 10 or #12 needle. Most folks would use it with no less than #69 bonded thread and a #16 or #18 needle, which works fine into 3 or 4 ounces of leather. Quote Share this post Link to post Share on other sites
leatherjo Report post Posted March 16, 2014 Wiz, thanks for the information! Bluesman, thanks for making the pdf. Can somebody pin Wiz' March 2 comment? Quote Share this post Link to post Share on other sites
