Seiko SKX013, SKX031 Mid size S Crown ? Its available NOW !

Edit : 11/2/2021 – new stock available !!

Its ready ! !

The Mid size “S” crown for SKX013, SKX031, SKX033 application….etc is now ready !
You can now supercharge them easily with the NH35, NH36, 4R36, 6R15….etc (not suitable for SKX023, 25, 27).

If you have read the below article, you will realised that similar to the SKX007.
The Seiko SKX013, SKX031, SKX033 crown and stem are also non-detachable.
Many of you has asked for a Mid size S crown which can accommodate a removable thread in stem.

After many months of working on it, its available now ! The mid size S Crown specially made for your supercharging mod !

The Mid size S crown (SKX013 / SKX031 / SKX033 – 6mm)

The Mid size “S” vs SKX031 crown

Similarly , they are made with “Double gasket” for added water resist application !
*The Mid size “S” Crown will feel firm and tight when install. It remove the ‘wobbly’ feels associated with the original crown.

Additional crown “Bottom gasket” for even more water resist assurance !

So there you have it guys ! You asked for it ! The Mid size “S” crown !

It is offered either

a) 1 x Mid size “S” crown (without stem)

Mid size S Crown – $25
International shipping (included)
Total = $25
Price : $25 (shipping inclusive) or you can make a payment here :

In case of technical issue, you can also revert.

My PayPal is


b) 1 x Mid size “S” crown” and 1 x NH36 stem (not installed, separated).

Mid size S Crown + NH36 Stem – $30
International shipping (included)
Total = $30
Price : $30 (shipping inclusive) or you can make a payment here :

In case of technical issue, you can also revert.

My PayPal is

If you need a NH36, its available.

Price : $70 (shipping inclusive) or you can make a payment here:

In case of technical issue, you can also revert.

My PayPal is

Thank you guys for the patience.

I have been asked several time to do a NH36 supercharge upgrade to the SKX013, a mid size Seiko SKX Divers.
SKX013 pix for your information how it looks like.
(below not my pix but from the net).

Pix of the SKX013 vs SKX007.

Information that i know so far :

A) The SKX013 aka 7s26-0030 (mid size SKX) has a crown-stem in similar format as the SKX007 (Note : cannot be detached).
For the NH36 super charge mod, you will need an aftermarket crown (if available).

B) You can use a SKX025 aka 7s26-0050 aftermarket crown BUT do note that the size is on the minus side (small !).

C) I believed the SKX031 aka 7s26-0040 crown may be better sized.

However, both the original SKX031 and SKX025 crown-stem are also not detachable.
(Note : cannot be detached).

Therefore, to Supercharge any of the above 3 mentioned watches (SKX013, SKX025, SKX031). An aftermarket crown/stem is needed.

SKX013 – 7s26-0030
SKX025 – 7s26-0050
SKX031 – 7s26-0040
SKX007 – 7s26-0020

You will see some Supercharge article of the above watches soon ! Do keep checking in !

Thanks for reading.

**mid size crown not suitable for SKX023, 025 and 027.

Interested, pls contact me here or email me at

If you are looking for a large size S crown for the SKX007, SKX009, SKX011 ….etc.

Its available here:

The mid size crown install on SKXA33 – customer mod pix


  1. Hello, First time reader looking for guidance on upgrading/modding my SKX013. How is this going?

    1. Hi, its still in the development stage.
      So far i had secured the crown design spec. and will needs some brain storming on the needed design.
      Afterthat will do some conversion.

    2. Hi Aaron, its available now !

  2. No rush, But I’m keen to see this happen!

    1. Thanks Jim.
      Me working hard to get at least the SKX013 and SKX031 happen. (the SKX025 is not too common).
      *Crown design is already firm. Currently getting it produce.

    2. Hi Jim, its available now !

  3. Very interested in this for my SKX031

    1. Do keep checking back for update. I am getting closer to having the S crown for SKX031 now. Shortly ………

    2. Hi Ian, its available now !

      1. Hi, Exciting news. OK so if I want to fit the NH36A movement to my SKX031, do I need the shortened stem? Or does the stem that comes with the NH36A fit?

      2. Hi, the mid size S crown will come with an uncut NH36 stem. It needs to be trim to fit.

    3. But option b) comes with a pre-trimmed stem, right?

      1. Hi option B as below.

        Couldnt offer the pre-cut stem as its different from the SKX007.

        b) 1 x Mid size “S” crown” and 1 x NH36 stem (not installed, separated).

  4. Paypal sent!

    1. Thanks. Received the PayPal with thanks

      1. Arrived today, it looks great. I’ll send some photos when it’s done.

      2. Thanks Jim. Look forward to your pix.

  5. This is awesome! Shot you an email with a few quick questions when you have a moment 👍🏼.

      1. Thanks for checking the precut stem length for me! Just ordered the crown 👍🏼

      2. Thanks for the support.

    1. Got it in this last weekend and installed it. LOVE it! Well made and perfect design! Thanks again.

      1. Glad you received it.
        Do send me some pix of it ! Thanks !

  6. Thank you for all the guidance, can you help me with this as i have arthritis in my fingers I want to fit the larger skx007 crown to the skx013, i know that i would have to open up the gap where the crown sits is this all i have to do, is the skx007 crown different measurements where it screws in and on where the stem screws in.

    1. Hi,

      The crown of SKX013 (6mm) vs SKX007 (7mm).
      Therefore in theory, its cannot be fitted.

      In order to use the SKX007 crown, you either :

      a) open up the crown guard gaping to 7.5mm
      b) remove the crown guard altogether

      The stem is not an issue as the SKX007 S crown + Stem can be adjusted to suit.
      The SKX013 crown tube will work on the SKX007 S crown.

  7. Would this crown fit a SPDC053 case and is it shorter than the standard 4.5mm length of the original, I love my 053 but would prefer the crown to stick out a little less.

    Also just wanted to say thanks as I received my new spring bars today no more clicky bars..

    1. Hi sir

      I am afraid this mid size crown does not fit your SPDC053. But we do have the “S” Crown slightly bigger which suit your requirement. You can check from my website

  8. Aaron Wheatley · · Reply

    Crown and movement purchased, paypal sent!

    1. Hi well received the payment, will deliver soonest. Thanks

      1. Aaron Wheatley · ·

        Hello, I have a question about the NH36 Movement and Crown I purchased. I received the Movement, but there was no Crown included. Are you able to send the crown also?

        Thanks, Aaron

      2. Hi, I just checked your order. Your payment of Usd70 is for NH36 movement only! Crown with stem is Usd30. Please re-check your PayPal details. Thanks

  9. NH36 movement, Mid Size S Crown and stem supplied and fitted to my SKX031 by the man himself. The crown still has the blue sticker on.

    I am very pleased.



    1. Thanks Ian 😊

  10. can the NH36 movement holder fit into the skx013 or do you swap the movement holder with the 7s26??

    1. Yes, it will fit.

      1. hysum zahreddine · ·

        thanks. i ordered a sxk013 crown from you. i have a movement already. thanks. just waiting for the watch as well. stem will have to be trial and error to size it correct. but if its like the skx007 it should be slightly longer then stock

      2. The stem will be trimmed to fit.

      3. i ordered a crown a couple days ago? is there a place to see shipping information?

      4. Replied in email.

      5. I dont see the email.

      6. Send yesterday.

    2. The movement holder will fit the NH36 and the 7s26.

  11. jonathan campy · · Reply

    If I choose NOT to upgrade the movement of my SKX013K2, will this crown fit just fine?
    Do I need anything else to fit this crown onto my stock SKX013K2?

    1. Hi, as the original Seiko stem is not detachable therefore a new stem is needed.

      You can get the 7S26 stem from me.

      1. jonathan campy · ·

        Ok great! I’ve never purchased from a wordpress, how would I purchase both from you?

      2. Email me at if you have any issue.

  12. Does your Mid size “S” crown” also fit the 7s26-0050 as well?

    1. The SKX031 / 033.
      Yes, it fit.

  13. When i have the 7s26 movement in a skx013, which stem do i have to use with the midsize? Does thiscome sith the crown?

    1. You will need a 7s26 stem. The original stem are not detachable. The Midsize S Crown is available with or without stem. Just make send me an email and let me know which stem you need after ordering.

  14. Hi
    I am interested in the mod.
    Have you checked the water resistance?
    adding more gaskets is not a guaranty of a better sealing.
    also, can you supply the specs for the gaskets for when these are to be replaced down the road?

    1. Hi, the Mid size S crown has a 3 gaskets, they are a much more water resist system than the previous. The Mid size S crown can be purchased with/ or without stem. Spare gasket are about the same cost as a spare crown, therefore I do have the parts.

      Since you are keeping the original crown, they can be swap back quickly.

      The purchase link are in the article. Thanks.

  15. happyharrysco1 · · Reply

    Hi There,

    is this SKX013 S crown still available?

    1. Yes, it’s available.
      My email is

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