Singer 431G Slant Shank Sewing Machine

The Singer 431G has been on my wish list for quite a few years now.  I patiently waited for one to come within reach and finally managed to secure one for a decent price and at a distance possible for me to collect it in person.  I took a bit of a chance with it as I didn’t manage to find out what accessories and plates were included before hitting the “Buy” button but I was lucky.  The only thing missing is the straight stitch plate but as I have many dedicated straight stitch machines, I don’t mind that.  The general (zig zag) stitch plate will work just as well and I do of course have a LOT of options when it comes to sewing a straight stitch on fabrics that require the smaller needle hole.  Of much more importance to me is that the chain stitch plate is present, which it is, together with the general plate and two cover plates and a full set of feet, cams and bobbins.


I always give new arrivals a thorough clean and service and removing the needle plate I discovered the ‘achilles heel’ of these machines: that is the fragility of the clamping pins over which the plates fit.  These are a mushroom-domed pin, cut vertically down in quarters, which allows the pin to squeeze together a bit when the plate is passing over it. I managed to snap off one quarter when I was lifting the needle plate free.

clamping pins

The complete, unbroken one is shown above left and right.  The broken on is shown at the bottom, together with two views of the broken piece to the right of the photo.

I doubt it can easily be fixed; it is too small to drill and pin and glue would not be sufficiently resilient to the constant strain of having plates squeezed over and prised off it repeatedly.  I shall just have to be careful not to dislodge any more.  It seems to hold absolutely fine with three quarters of the pin and a quick Google search shows me that this is a common problem.  If sufficient sections come free as to make it unusable I shall simply drill out the stumps and tap in a straight pin of correct dimensions to fit the holes in the needle plate or else tap in a threaded insert and use some ordinary needle plate screws.

Researching this machine before bidding, I found very little.  I’m not particularly surprised by this as what I did find out was that they had a very limited production run in the early 1960s.  I can’t find a serial number on her at all…I’ll continue to look but I’ve searched all the usual places.

Those of you who are familiar with my machine reviews will know how much importance I place on facts and figures so here follows some definitive data about the serial numbers of the accessories and plates which came with my machine.  I can’t guarantee that all of them are original but the plates all fit and so do the feet.

  • Chainstitch needle plate:                    Singer 503601
  • General (Zigzag) needle plate:          Singer 503583
  • Straight stitch needle plate cover:     Singer 507753
  • Zigzag needle plate cover:                 Singer 503541
  • Special purpose foot:                          Singer 161167
  • General foot:                                      Singer 172075-001
  • Button foot:                                        Singer 161168
  • Seam guide:                                        Singer 161172
  • Cording (Zipper) foot:                         Singer 161166
  • Narrow hemmer:                                Singer 161195
  • Multi-slot binder:                                Singer 161420
  • Ruffler:                                                Singer 161581
  • Straight stitch foot:                            Singer 170071-001
  • Darning foot:                                       Singer 161596
  • Five black top hat’ cams numbered 1-5.
  • 4 type 66 metal bobbins.
  • 1 small screwdriver
  • Small tube of Singer oil.

This is a composite photo of the chainstitch plate.  Its serial number is 503601.  I show it from three different angles – side, top and bottom, with the bottom photographed twice to show the range of motion in the swivelling piece that forms the chain stitch.

chain stitch plate

This photo shows the chainstitch.  It is beautifully formed and not difficult to do.

chain stitch

The bobbin is removed and the upper thread passed through the extra tension hook that is immediately left of the takeup lever.

chain stitch thread guide

I loosened the tension and used a stitch length of around 8 stitches per inch.  Using a longer stitch length increased the likelihood of dropped stitches, as did a hesitation in pace whilst sewing.

The thread I used was just a cheap polyester but I was nevertheless impressed with the results and look forward to experimenting further with this as it was indeed the primary reason I wanted this machine.

I will scan and publish a full version of the manual when time permits but in the meantime, here follow the pages relating to the chainstitching:






The top hat cams are the old style ones with two apertures in the brim.  I am indebted to Barbara at Oldsewingear for her excellent blog post explaining the differences here:  I can confirm her advice that the 431 takes the ones she describes as Type 1.

primary patterns

These cams supplement the primary stitch patterns which are built into the existing, metal cam stack which sits below the area where the plastic cams may be fitted.  The patterns are shown under the lid but further fine-tuning may be done using the stitch length too.

The manual advises to use the ‘Special Purpose Foot’ for these stitches as the raised area below the foot allows room for the depth of the satin stitches.

special foot

I do not presently have a straight stitch needle plate.  I believe that its serial number may be 503582 but have no way of checking this.  If any of you have one and can check it, please let me know.

I must draw attention to the fact that the lettering “AK3” appears on the top of the chainstitch plate as well as the straight stitch one so if you are seeking one or the other, do check that you are buying the correct one.  The best and easiest way to tell them apart is that the chainstitch plate has a slightly oval needle hole and more notably a pivoting bar underneath that helps form the chainstitch.

Another common confusion that has come forwards in my research is the subject of replacement needle plates and whether the superficially similar T&S plates are compatible.

Instinct is telling me that I can see enough differences to make it unlikely that the T&S ones could be substituted but I can’t say for certain unless one came into my possession so that I could try it.  Helen Howes (my favourite UK supplier) has several on her webpage and I can spot four main differences straight away, some obvious and others less so.

The 431 zigzag plate and the cover plates all have a rectangular area cut away on the underside, with a further two corners cut away further so that the base of the sides flared out at 45 degrees.  Lining it up with the feed and the bobbin case I can’t see any reasons for this but I nevertheless can’t ignore it as possibly relevant for the plate to fit.

This photo shows the zigzag and straight stitch cover plates, both front and back.

zigzag and straight stitch cover plates

This photo shows the area cut away from the underside of the bobbin plate.

bobbin plate underside

Some of the plates for the T&S have measurements scored both sides of the needle hole.  The 431 plates have measurements scored on the right hand side only, as shown here in this photograph of the general (zigzag) plate.

general (zigzag) plate

This photo shows the bobbin and needle plate together, top and bottom, showing how the two plates fit together.  At the bottom of the photo, the underside of the needle plate is juxtaposed with the area which is covered by it.

plate shapes

Where the needle plate meets the bobbin plate, the curved sides of the 431 plates reduce width through a 90 degree turn.  This edge is smooth.  Some of the T&S plates are shaped similarly but have an extra piece of metal running below the edge of the bobbin plate, perhaps to improve the fit.  I would be cautious of assuming that these extra pieces would marry up ok with a bobbin cover not designed to be used with it.

The holes for the clamping pins may be in a slightly different position; it is hard to tell.  The back of the feed dog holes on the 431 plates looks as if it is slightly closer to the back edge of the plate than on the T&S plates.  On the 431, the distance between the rows of feed teeth looks to be the same as between the feed and the back of the plate.  Measuring confirms it – the distance is 2mm in both cases.  These distances don’t look equal on the T&S plate.

plate dimensions

Because it is impossible to accurately gauge size from photos, I have also measured the zigzag plate.  It is 63 x 30mm.  Mine has obviously suffered a bad needle strike in the past and I shall certainly replace it if I ever get the chance but as spares are rare, I’m not holding my breath for that…

The feet and accessories are all generic slant shank ones that I think will be able to be shared between any other slant shank machines.

The machine itself was in excellent cosmetic condition and did not need a great deal of cleaning.  Despite this, I have taken all of her plates off and removed a great deal of fluff and a couple of needles from the base of the free arm.  I was very happy to see how easily this may be cleaned out.  The whole bottom of the free arm casing is a single piece, held in position by one bolt so it is very easy to access this area to clean and service it.  The hook and bobbin case look at though they would benefit from a more thorough cleaning than I have been able to do so far but as I am unfamiliar with this style of bobbin and hook I will wait until I have educated myself a little further before attempting this.

The machine is now clean, oiled and ready to use.  That said, I intend to run her in gently.   It is certainly a good few years since she was last used and she has spent the last six months in a garage.  Once I have properly run her through her paces I will report back with a post relating to performance, its neatness and quietness and how well she compares with my other machines.

I have not weighed her, but she is made from aluminium so whilst solid, is lighter than my cast iron machines and also lighter than my Bernina 830 Record, although similar in size.  The extension bed is much easier to remove than the one on my Featherweight 222k. It is released by pressing a small button on the machine bed, close to the rear of the machine pillar and slides back on again very easily.  The accessories are stored beneath an aluminium lid in the extension bed which opens up to reveal the compartment within, with space for the cams, oil, feet and attachments.  The motor is housed vertically within the pillar and is easily accessed by removing the single bolt which secures the oil pan below.  All in all it is very sturdily made and I am impressed.

Copyright of the blog owner 2017

31 Comments (+add yours?)

  1. Steve Lillegard
    Sep 07, 2020 @ 16:47:57

    To determine the date of manufacture, look at the date on the side of the motor that faces the electrical plug in. There’s not much space but you can see the month and year. Mine is “64”.


  2. Susan Wingert
    Oct 09, 2019 @ 11:05:48

    I was extremely lucky in purchasing a 431g recently with all the attachments still intact in the built in storage box, including the chainstitch plate. However, when setting up the machine, I noticed that the slide plate was loose and on inspection, found that the small metal connector piece that is screwed onto the underside of the slide plate had sheared off at the screw. Is anyone aware of a replacement that could work? If I can’t find something, I will have to use tape to keep it closed. Thanks for any help!


    • Devil_in_Disguise (@monikakremer)
      Jul 22, 2020 @ 14:33:18

      I am not sure if you’re still searching. I assume you’re talking about the throat plate / needle plate pins? Those are notoriously fragile on the 431Gs. I just ordered mine from Helen Howes in the UK. Not sure if links to shops are allowed, but you’ll find her on google. She has some new manufactured versions. Didn’t find them on the website so I emailed her. They are currently on their way to me for 5 British Pounds each (+3 for shipping)


  3. Fablab 3Lapins
    Sep 26, 2019 @ 09:38:10

    Hello, and what’s about a reminder to remember the reminder 😉
    sorry for the joke! we have bought a 631G …which is a marvelous technical little thing; we are in France and it’s impossible to find parts or documentation here about this machine. We have a chain stitch bobbin case too ( a little bit damaged by needle; don’t know why or how) but no documentation.
    If you can find some minutes to scan your, it will be so great 🙂


    • Fablab 3Lapins
      Sep 26, 2019 @ 09:41:47

      ooops a 431G ( I have a 631 too but in poor condition


    • Offspring
      Sep 26, 2019 @ 09:46:28

      Hi Fablab! You’re right about me needing a reminder about the reminder and I will indeed try to scan the whole thing soon. Unfortunately I don’t think it will help you with your 631G though as I understand that the chain stitch mechanism is completely different. I’ll let you know if I discover anything that might help you though. The 631G looks like a great machine. 🙂 x


      • Fablab 3Lapins
        Sep 26, 2019 @ 20:23:00

        wonderfull! so exited 😉
        we are really in love with the 400 serie; 600 are definitively too young for us (500 seem great too…we are looking for)
        do you know if the 431g came with the both bobbin case (503602 – chain stitch possible and 172082 – normal case) or only with the 503602 and 431 noG models with only the 172082?

      • Offspring
        Sep 26, 2019 @ 20:28:15

        Hi Fablab 3Lapins, unlike some machines which use a bobbin case insert (usually referred to as a “spider”) for forming a chainstitch, the 431g forms it using only the special needle plate and the extra thread guide to the left of the thread uptake lever. No special bobbin case at all. I’ve scanned and uploaded the manual as a new post, by the way, so that is ready for you to see now. 🙂 x

  4. Patrick Moody
    Jul 17, 2019 @ 09:57:57

    I recently acquired a 431G which came with the chainstitch plate, but no instruction book. Did you ever get round to scanning and publishing yours? Those I’ve found online (named 431 – without the G) don’t include the pages relating to chainstitch which leads me to believe they may be for a different, perhaps American, variant of the machine that didn’t offer this feature. Thank you.


    • Offspring
      Jul 17, 2019 @ 12:34:46

      Hi Patrick, I haven’t scanned it yet but now you’ve reminded me, I’ll set myself a reminder to try and do it over the coming weeks. Watch this space. 🙂


  5. Sally Gulbrandsen
    Nov 29, 2018 @ 23:31:58

    Thank you for an interesting article. I recently acquired a 611g Singer Sewing Machine without the chain stitch attachments. Could you please tell me which pieces I need to source. I downloaded a manual which talks about removing the throat plate and bobbin and inserting the chain stitch retainer, depressing the latch and turn to the left and then insert the chain stitch throat plate. I cannot seem to find anything which resembles the chain stitch retainer shown in the very poor illustrations. Could you possibly add a photo of your own 611g chain stitch accessories to this article, please? Do you have a number on the accessory box and tools which came with your machine? Perhaps I can source a complete set if I know which models are compatible with this German-made Machine. Thank you in advance.


    • Offspring
      Dec 03, 2018 @ 21:26:56

      Hi Sally, I think the 600 series uses a different system for chain stitching. From memory, it uses something called a ‘spider’ that replaces the bobbin so that might be the retainer. The 431g doesn’t use one of those; it just uses a special throat plate and an extra thread guide for the top tension.


  6. Liz Sanneh
    Sep 16, 2018 @ 12:42:13

    I have had a 431G for the past 49 years – I had used this model at school for GCE Needlework and had the good fortune, when I reached 21, of having some money to buy a machine. I visited my local Singer shop in Reading (long gone now) and for the princely sum of £21 bought it on hire purchase. I have been so attached to this machine and use it frequently. Now that I have arthritis, I have had to also buy a lighter-weight newer model which is easier for me to load in and out of the car when I visit family who have jobs lined up! The new one is not a patch on the 431G and I have serviced it myself every year – It has been a real boon with three denim-wearing sons, and they have all learned to sew on the machine in order to mend their own jeans. Sadly my daughter was not interested in learning, but her daughter is now sewing at home and able to produce lovely items so maybe the desire just skipped a generation. Looking forward to many more years with this sturdy machine – I have it in a Horn cabinet with the air lift which is such a help as I have got older. I can’t wait to retire and spend every day sewing!


    • Offspring
      Sep 16, 2018 @ 12:47:21

      What a lovely story, Liz and thank you so much for sharing it. I hope that when you’ve finished with your 431g you can pass it on to your granddaughter so that she can continue to put it to good use. It’s so satisfying to get more than a lifetime’s use out of what was – at the time – a considerable investment but the quality definitely shows through. 🙂


  7. Jessie Cunliffe
    Jul 13, 2018 @ 10:06:54

    I have a Singer 611g, which is a later model, and I love it. The needleplates looked similar and I have a spare SS plate which I thought would fit your machine. I’ve just looked, and unfortunately, they are different numbers, and the measurements are different, although they look the same. If I come across one I’ll pass it on.



    • Offspring
      Jul 13, 2018 @ 13:53:59

      Thanks Jessie, that’s very kind of you! I’m also grateful for the information about the measurements being different as I’ve been tempted on a couple of occasions to buy a 600 series one on the off chance that it would fit so at least now I know to knock that idea on the head. 🙂 x


  8. freddowasher
    May 16, 2018 @ 12:49:45

    Thank you so much for this incredible & very detailed post. Just been looking at a Singer 431 here in the UK & hope I get to buy it. Who knows with Ebay. Thank you so much for helping me decide to try to buy it. If I’m unlucky I’ll keep watching for one.


  9. Madeline Shepherd
    Dec 14, 2017 @ 16:22:12

    As a matter of interest, do you have the part number or any photos of your machine’s bobbin case? My 431G came with a bobbin case that works, but is marked Gt. Britain and doesn’t look right compared to the rest of the machine. I suspect the previous owner might have mixed it up with another Singer bobbin case.


    • Offspring
      Dec 15, 2017 @ 15:00:06

      Hello Madeline, I can’t see any part number on mine, I’m afraid but have taken a photo of it for you which I hope will help. I cannot upload it here so will email it to you. 🙂


    • Colleen Sims
      Sep 19, 2018 @ 22:30:29

      The bobbin case part number for the chain stitch feature is 503603. I have a question for all who read this blog and have 431g machines. Have you found a reliable parts or process to replace/repair the needle plate pins? My machine came to me with on pin 3/4th intact and the other gone all together. So I tape the needle plate in place. Thank you


      • Offspring
        Sep 20, 2018 @ 08:19:54

        Hi Colleen, I think I read somewhere that the pins could be removed from underneath (I suppose there’ll be a grub screw to loosen) and replaced by a similar type from a later model which used solid rather than split-headed pins. I’d have to seek out the information again to remind myself which model number it was but is likely to be one of the 600 series. It’s definitely a weak point on an otherwise great machine. The inventive, make-do-and-mend side of me feels that any pin could be used over which the plate could fit and be lifted loose therefrom, providing the plate wasn’t so loose that it could waggle and lift free. I’ll see if I can find my original source today and if I manage to, will report back.

      • bicyclz
        Jan 11, 2019 @ 09:05:40

        I’ve been looking for a solution to the broken fixing pin problem problem for ages. They are like hens teeth & so I bought a complete cosmetically challenged machine to solve the problem.

        So I now have one machine with both pins having only one segment each side & I have rotated the single segment to the outer sides, which effectively locates the plate laterally.

        (They are held in place by grub screws, which need a longish, thin, flat bladed screwdriver to remove. They can be very tight!)

        To avoid rattles I’ve tried BlueTack under the plate which does enable normal use in my case. It’ll run at full speed on zig-zag quite safely I find.

        I’m currently experimenting with some small magnets fixed to the alloy casting underneath… Might work: )

  10. Linda Chandler
    Nov 04, 2017 @ 16:25:05

    I just purchased a Singer 431G, and presently it is in transit. I feel like a 4 year old at Christmas, but thankfully I’m not wetting the bed. LOL When I receive my machine and I’m able access the working condition I will follow up with you. Before I can do any work, I will need class 66 bobbins, and would like to purchase some good quality metal bobbins. Where do you purchase your bobbins? Please let me know. I would truly appreciate it. Thank you


  11. Rachel An
    Oct 22, 2017 @ 02:23:43

    I can confirm that the part number for the straight stitch plate is 503582. By any chance, have you had the opportunity to run your machine yet? I ask because I am wondering if the noise mine makes is typical. The bobbin case rattles around a little in the hook assembly and makes a clicking sound during every revolution. No adjustment I have made has seemed to help. I’ve been wondering if that is typical of these machines, or if something is off with the hook assembly, the hook race, or both.


    • Offspring
      Oct 22, 2017 @ 09:04:52

      Thanks for the confirmation, Rachel. Yes, mine is a bit clicky too. I used to get the same with a 99k I owned. Like you, I also wondered whether it was something that had developed a little ‘play’ and needed to be tightened up somewhere but I suspect it’s just how they are if yours does this too. I’m still running mine in and doing minor adjustments as I go. I’d really like to take to remove the hook and the feed dogs and strip down and clean it but I need to find a very clear (and clear-minded) day before I can attempt that. 😉


  12. Brittany Jenkins
    Oct 15, 2017 @ 13:56:40

    I just got my own Singer 431G, and I found the serial number today. It is on the bottom below/near the large piece that unscrews from the middle. (I’m still learning sewing machine terminology, so if this piece has a name, I don’t know it offhand.) Mine starts with PB. Since it was German-made, I can’t seem to pinpoint if it was made in 1964 or 1965 (the two year span these machines were made), but I’m glad I finally found it!


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