Changing needle type · Needles

Convert your vintage machine to modern needles – for needle clamps with side insertion

Many vintage sewing machines use old types of needles that are no longer being made. This is very annoying because it forces you to retire an otherwise fabulous machine for the stupid reason that you can’t find the needles for it!

But fear not, the solution is here. You can give your dearest the gift of life – convert her to modern needles.

This post deals with needle clamps where the needle is inserted on the left into a groove in the needle bar, and is clamped between the needle bar and the needle clamp. This method won’t work for needle bars with an integrated clamp where the needle is inserted into the needle bar itself, as shown in the left photo.

First, a fair warning: once you start the conversion, there is no way back. You will need to complete it, or your machine will never sew again (unless you replace the needle bar to get back to the way things were before you started). You will need some drilling, grinding and soldering skills, to acquire before you start – it’s not hard, but please practice on something other than your true love. You will also need a steady hand, so calm down, take a deep breath, meditate, say a prayer, shoot some zombies – do whatever you do to steel your nerves – and let’s begin!

The tools

Besides the usual screwdrivers, you will need one tool to do the work (a mini-grinder) and another one to fix your oopses (a soldering kit). Both tools can be of plain DIY quality, and it’s best if they are light and small – the beginners’ stuff (more advanced stuff is usually heavier and requires some real skill to handle).

This is my mini-grinder set. You can see here how often I use it – everything is still new! 🙂 The bits we need for this job, are the engraving tips – it’s the row above the green and orange grinding stones.

The skill to build up is to steadily grind a steel bar with one of those engraving tips, making a straight line without bumps, that is equally deep along its entire length.

​This is the fixer-upper kit: a simple soldering iron, some solder and a couple of hand files. Again, nothing fancy.

The skill to have here is very basic: how to solder, i.e., how to get the tin to stay where you want it instead of building more and more burned up layers on the soldering tip. Look it up and try it out first, if you’ve never done it before.

Make a plan

Of course you can just start grinding and soldering and hope for the best, but it’s better to prepare and thus avoid the worst.

The important point is to determine the difference between the old needles and the new ones, as this determines what you need to do. A large number of old machines are made for 12×1, 13×1 or similar needles, which have a thin shank, so our modern needles with a thick shank don’t fit.


For more information on needle types and their measurements, names and IDs used by different makers, see this fantastic cross-reference at ISMACS.

A particularly important point is whether you are changing the type of shank: from round to flat or visa versa. If you are converting from 12×1 or 13×1 needles to modern “standard domestic” 15×1, this is exactly what you are doing: switching from a round shank to a flat shank.

It is important because the tip of the needle will now be displaced: in a round shank needle, the tip is aligned with the centre of the shank, but in a flat shank needle a chunk of the shank is “missing”, and so the tip is closer to the edge on the flat side than on the full curved side.

So, the groove for a flat shank needle needs to be asymmetric with respect to the tip of the needle, and it must be oriented correctly. Which brings us to the second question: is your machine side-facing or forward-facing?

Now it gets complicated to describe all the possible needle and needle groove orientations, and I think it would be very confusing. So I am going to focus on transverse shuttle machines: they are forward-facing, with a groove on the left side of the needle bar.

1905 Stoewer TS, Germany

These machines often follow Singer’s design and use 12×1 or 13×1 needles, now extinct, so they need converting. If your machine has a different configuration, read through the planning stage for the transverse shuttle machine and adapt it to your situation. The execution stage will be very similar.

On a forward-facing machine, the needle is inserted with the flat side of the shank to the back, so that it is threaded front to back. Turn the machine sideways with the groove on the needle bar facing you. To keep the new needle properly centred, you have to grind away more material on the right side of the groove than on the left side.

You will also need to make the groove deeper to accomodate the extra shank thickness of 15×1 needles, so that the tip would come out in the same spot as before.

Finally, compare the needle length, namely the butt to top of the eye distance. (If you don’t have the original needle in the flesh, so to speak, refer to the ISMACS cross-reference for details.) If the needle length is different, you can do two things to compensate: either raise or lower the needle bar, or make your new groove longer or shorter than the old one.

Changing the needle bar height is often the easier solution, but it cannot always be done. Sometimes the screw that holds the needle bar in place, does not just clamp it, but actually goes right through it. Sometimes it is permanently stuck, and sometimes the needle bar has a cut-out that drives the take-up lever and thus cannot really be moved, except by just a little.

Needle bar on a Vesta B high arm model driving the take-up lever

Decide what you are going to do before grinding, and mark the height of the needle groove that you want to make. It is best to make it with a straight end rather than domed, because not all needles are domed.​

The plan is then to grind the groove on the side of the needle bar and to keep checking that the needle tip comes out in the centre of the needle hole, and that the needle remains straight, when seen from the front and from the side.


On paper, it’s very simple: just follow the plan. In reality, it is tricky because you cannot always test properly since round needle clamps often need to be adapted to the new needle, or they won’t clamp, but it can only be done after the groove is completed, which needs testing with the needle clamp… A bit of a chicken and egg situation. Which is why I told you straight away that you’ll need a fixer-upper kit.

I would suggest to first make the groove to the best of your ability, and test it by pushing in the needle with your finger. Try to push it in as firmly as possible along the entire groove, this should reveal most digressions. Don’t forget to check both from the front and from the side every time – it’s very easy to get side tracked. It is also helpful to examine the groove with a magnifying glass, or take a close-up photo and magnify that – some small but significant bumps are hard to see with a naked eye. If you have a bump in the middle of the groove, the needle will balance on it like on a pivot, and will sit slanted.

Can you see the bump in the middle of this groove?

When you think that the groove is reasonably good, turn to the needle clamp. It may work just fine as it is, then you’re lucky. If it is too small and doesn’t fit over the new needle (which now protrudes outwards more than before due to the thicker shaft), grind or file away a little on the inside of the clamp so it would fit. If the clamp doesn’t hold the needle firmly, solder some tin on the inside of the clamp and then grind that away until the clamp works.

Then check your needle again. The groove may require correction! If you find that you made it too deep or too wide, solder some tin into it, then grind or file until you’ve got the right depth.

This is not an exact process, I’m afraid! But you will get a good result in the end.​

If you decided to adjust the needle bar height, insert the needle, loosen the screw(s) holding the needle bar in place, and move it such that the hook (or the tip of the shuttle) meets the needle just above the eye.

Don’t forget to do the sewing test! 🙂


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