Seam class specifications

Updated 2/18/09 American & Efird (the thread company) has a much more user friendly six page pdf seam class chart using the older military designation which is the one that most people still use. The first page is an index; subsequent pages show diagrams with the needle path shown in red. This pdf is standard reference material to keep on hand when filling out forms and instructions to contractors. The ASTM system mentioned below organizes seams entirely different with numerical designations and is not used quite as much.

I keep forgetting to mention that I have all of the seam class specifications and pictographs in pdf file format available for download on my site at Designer-Entrepreneurs. These specs were originally developed in accordance with standards found acceptable by the US military and were adopted for use by military contractors over 50 years ago. In fact, one would think it’s time for everyone else to use them too. These are the standards formerly known as designation 751.a and cost over $50 from the GPO but now, here you can get them free. Even if you’re not one of those twisted individuals who enjoy reading and collecting specs -like yours truly- these will be useful in communicating desired seam details to your sewing contractor, eliminating any ambiguity regarding required product quality standards. To whit, specifying these standards in a contract make your product quality specs iron-clad so be nice and print the pictographs of the specific standards you want and provide them to your contractor because it’s unlikely they have them handy.

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  1. Carrie says:

    Aha! Finally someone else who is using seam class specifications! I’ve been trying to integrate these into our spec sheets at work but our sewing contractors look at me like I’ve grown a third eye. I think it is a brilliant tool for being specific about the expected results when sending a garment out for sewing. I’ve made it mandatory for all styles being sent offshore because it provides answers when I can’t be there in person. Writing out the order of operations using this guide leaves little room for interpretation and it’s a visual system so it’s useful when there are language barriers (i.e. offshore manufacturing). It’s also a great thing to have if you encounter a major quality problem and need to get a credit from your sewing contractor. I do hope your readers take a look at it. It would be great if we could use this system in the industry the same way we use Pantone numbers.

  2. Sandra B says:

    I’ve just starting teaching two short courses at one of our technical colleges. They are sort of recreational but a lot of people doing the course are trying to get a jump on a career in the industry. So, these have come in handy. I have the seam class specs from your site, but I couldn’t quite understand some of the details. This update has helped a lot.

  3. Sarah B says:

    Great condensed seam chart! It’s much easier to show people what you’re talking about with a 6 page hand-out, as opposed to the bazillion page ASTM D 6193 version… which has caused most of my co-workers to lose all color, get bulging eyes, or just say “no, nevermind,” right from the start. Thank you!

  4. Paul says:

    Thank you for the links and valuable information in such a concise form. In case anyone wants to know as much as they can about thread, the link to American & Efird has some really good information on the site. They probably have more information than most can digest.

  5. Julio Novo says:

    The content you post on this site is extremely useful, but this article specifically stands out. To an industry outsider like myself, seam specifications seem like such a small detail that I would not even think to ask if a standards chart exists.

    Thank you for answering a question I did not even know I wanted to ask.


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