Seiko Nautilus Mod
The Seiko Nautilus Mod AKA the “Seikonaut” has recently become a fan favorite in the modding world. With the release of numerous Nautilus inspired cases compatible with Seiko parts, you’re bound to see this built time and time again.
You may be wondering where to source parts, or even how to build it? Well don’t worry, you’ll be able to follow along with us as we build a “Seikonaut” step by step!
What Mod Parts Will I Need?
Believe it or not you only need 9 parts (not counting the stem of course) to build your own Seiko Nautilus Mod! And since the sapphire is included with the case, you really only need to buy 8 of those parts.
They are as follows:
- NH35 hands
- Flat Sapphire (included free with case)
- SKX007 Chapter Ring
- Seiko Dial
- NH36 Movement (or NH35 depending on your dial) stem included*
- SKX007 Crown
- SKX007 Caseback
- Nautilus Conversion Case
- Nautilus Compatible Bracelet
Once you have purchased these mod parts, you’re one step closer to building your own Nautilus mod!
Nautilus Style Case For SKX007
First you will need to pick out which Nautilus style case you are going to use for your build. With so many vendors on the market there are plenty of different colors and finishes to choose from.
Originally we were going to use a two-tone black and silver Nautilus Case, but we had a beautiful gold dial without a home. So, we changed directions and used a gold and silver two-tone Nautilus Conversion case instead.
What Movement Should I Mod With?
Which movement you should choose to mod with is completely dependent on which dial you are going to use. Since we are using an OEM Seiko Dial from model SNKK94 with day and date window, we will need to use an NH36 movement.
The same goes for the other available movements. Here’s a quick break-down of which movement to use with which dial:
- For a date only dial you will want to opt for an NH35. However, you can still use an NH36 movement with a date only dial. The dial will not interfere with the day wheel.
- For a dial with no date window, most will use an NH38 movement. However, you can use an NH35 and an NH36 movement with a dateless dial. If you choose to use an NH35 or NH36 just know that you will hear the “phantom date change” at midnight.
- For a skeleton Nautilus mod you’ll want to use an NH70 movement which is skeletonized. Don’t forget you’ll also need a gray movement spacer if using an NH70 movement.
No matter which movement you choose to use, they all have the same specs from the factory. This means that an NH35 is not better than an NH38 or vise versa.
Once you have your movement, put it into a movement holder like the Watch-Modz NH Movement holder we used.
How Do I Install A Seiko Dial?
Installing the dial might be one of the easiest parts of this whole mod. For us, it was extremely simple. This is because the dial came out of a 3:00 crown Seiko case. The dial feet already line up correctly so it was as easy as just setting the dial onto the movement.
Now, if you are going to use a dial that has 4 dial feet you will need to cut the 2 feet you wont be using. Alternately, if you have a dial with NO dial feet, you will need to use dial dots.
If you are new to modding and do not know how to perform this task, please read our tutorial page on cutting dial feet.
What Hands Should I Use For My Nautilus Mod?
Hands will be the easiest part to pick out for your mod. This is because the hands you choose are based off of your personal preference. As long as you buy NH35 hands and they are meant for 28.5mm dials, then you will be good to go.
As a general rule of thumb, modders like to pick hands that match well with the hour markers. It helps the parts seamlessly blend with the completed design.
With that in mind, we have chosen gold baton style hands to match the gold baton style hour markers of the dial.
Chapter Ring And Sapphire For Seiko Nautilus Mod
Thankfully the Nautilus case from Watch-Modz comes with a free sapphire crystal and gasket set. One less thing you’ll need to buy for this mod. Another thing that helps the Watch-Modz case stand out, is that it accepts SKX007 Chapter Rings. This was important for us as we wanted to use a polished gold chapter ring to match the dial and hands.
Installing the Sapphire can be difficult for most beginners. However, you wont have to worry about that with the Nautilus mod! The sapphire crystal slips right into place, even with using the cheap blue lever crystal press! Just make sure you install your chapter ring before pressing in the crystal.
If you need a step-by-step tutorial of crystal installation please read our tutorial page.
Which Crowns And Casebacks Fit?
The great thing about these Nautilus Conversion cases are that they take SKX007 crowns and casebacks! This makes picking a crown and a caseback very easy.
We wanted to maintain that nice two-tone vibe the build has going on, so we chose a gold coin crown, and a Watch-Modz slim gold caseback. The slim casebacks are excellent when it comes to added comfort and reduced height off your wrist.
What Bracelet Will Fit The Nautilus Cases?
The Seiko Nautilus Case comes with a 20mm lug width and a unique shape. Because of this, the standard SKX007 bracelets will NOT fit these cases! That’s ok though, because there are bracelets that will fit this case on the market. Watch-Modz carries a few different styles of nautilus bracelets, including steel oyster, and FKX fitted straps. For this Nautilus mod we opted for the silver oyster nautilus bracelet.
Completed Seiko Nautilus Mod
That’s it, you are all finished building your Seiko Nautilus Mod! This mod is quick and easy, no bezel to install, no insert to line up, and the variety of parts are endless. We are very satisfied with how our Nautilus mod turned out and I hope you will be too. Let’s take a look at the finished product!
