When most people think of a Seiko mod, they picture mechanical NH35/36-based builds. But in recent years, the rise of the quartz Seiko mod has opened up new possibilities—especially for budget-conscious or beginner modders.
Quartz movements offer low cost, greater reliability, and easier assembly—all while still allowing you to create a beautiful, fully custom watch. In this guide, we’ll cover the most popular quartz movements used in Seiko modding, including the VH31 sweeping quartz and the VK63 chronograph, and show you how to get started.
Why Mod with a Quartz Movement?
There are a few key reasons why modders are turning to quartz Seiko mods:
Lower Cost
Quartz movements are inexpensive compared to automatics. If you’re just starting out or prone to mistakes while learning, the low cost makes them a safer option.
Better Accuracy
Quartz watches are much more accurate than automatics, drifting just a few seconds per month (vs. daily drift for mechanical movements).
Easy Assembly
No rotor, no winding, no balance wheel to worry about—quartz movements are easier to work with and install, especially for beginners.
VH31 Sweeping Quartz – Perfect for Simple Mods
The Seiko VH31 is one of the most popular quartz movements for modders looking for that “automatic feel.”
Key Specs:
- 4 ticks per second sweeping second hand
- No date function
- Reliable and compact
- Works with NH35/36 cases using a movement spacer (available on AliExpress)
- Requires SR920SW or 371 Battery (cell).
It’s a great movement if you want a clean three-hand watch without a date. The sweep looks smoother than standard quartz, though it’s not as fluid as an NH automatic (4 vs. 6 ticks per second).
Movement Spacers – Quartz Seiko Mods
To fit a VH31 quartz movement into an NH3X automatic case, Seiko modders can use specially designed movement spacers. These spacers are readily available on platforms like AliExpress in a variety of sizes to match the internal dimensions of different NH cases. If the seller doesn’t list the inner diameter of the case, it’s best to wait for the case to arrive and measure it using calipers or a digital vernier. Then, order the correct spacer to ensure a secure, centred fit for your quartz build.
Hand Sizes for VH31:
- Hour: 1.20mm
- Minute: 0.70mm
- Second: 0.17mm
Keep in mind: VH31-compatible hands are different from NH series hands, so you’ll need to source hands specifically for this movement, there are limited options on Ali Express at the moment but we imagine this will grow with time.
Need Tools? If you are new to modding and want to get started we have put together a starter tool kit that has everything your need for less than £45.
VK63 Quartz Chronograph – For Modders Who Want More
Looking for more complexity in your quartz Seiko mod? The Seiko VK63 is a mecha-quartz chronograph movement that offers stopwatch functionality and classic subdial layouts.
This movement gives you the vintage Daytona-style or Speedmaster aesthetic—at a fraction of the cost of automatic chronographs.
Tip: When buying a case weather you want a bracelet at this point or not. It is best to buy both the case and bracelet set as this will guarantee the best fitting bracelet. If you do not you will find it very hard to get a bracelet in the future – there is a blog about here are seikomodder.com.
Why Choose the VK63:
- Real chronograph function
- Mecha-quartz hybrid: mechanical chronograph feel with quartz accuracy
- Tons of AliExpress case options (Daytona-style , Speedy-style, Panda Dial, etc.)
- Very budget-friendly for what it offers
VK63 Hand Sizes:
The Hands for Seiko Quartz Chronograph mods (VK63)can be found on Ali Express. For modders looking for hands that they may not find listed the hand sizes below will be useful.
- Hour: 1.50mm (compatible with NH35/36)
- Minute: 0.90mm (compatible with NH35/36)
- Chronograph seconds: 0.34mm
- Subdial hands: 0.28mm
This means modders can reuse NH-compatible hour and minute hands with the VK63, which simplifies sourcing. However, the second and subdial hands are unique sizes—so you’ll still need VK-specific chronograph handsets.
There are numerous VK63-compatible cases available from sellers on AliExpress. Many include pushers, crowns, and spacers specifically built for this movement. Just search for “VK63 case” or “VK63 chronograph mod case.”
Dial Compatibility for Quartz Seiko Mods
If you’re using the VH31 as the workhorse of your Quartz Seiko Mod, you’ll need to avoid dials with a date window—since the movement doesn’t support a date complication. Most NH35/36 dials without a date window will work fine.
For VK63 builds, you’ll need a dial with:
- Cutouts for subdials at 3, 6, and 9 o’clock
- The movement date window unless your case and dial match perfectly
Many AliExpress listings for VK63-compatible dials and cases are clearly marked, making it easier for first-time modders to match everything properly.
If you have a dial that doesn’t have any dial feet you can follow this guide to install a dial using sticky dial feet.
Planning Your Quartz Seiko Mod – What to Know
Whether you’re modding for fun, gifts, or even resale, here are our top tips:
Use NH Cases with Quartz Spacers – Quartz Seiko Mods
Movement spacers are essential for fitting the VH31 quartz movement into NH35/36-compatible cases. These plastic or resin rings are readily available on AliExpress in various sizes to suit different case dimensions. Since not all sellers list the internal diameter of their cases, it’s important to either choose a spacer listed as compatible with your specific case—or, if unsure, wait for the case to arrive and measure the internal diameter precisely with a set of vernier calipers before ordering the correct spacer. This ensures a snug, secure fit and avoids damaging the movement or dial during assembly.
Match Hands to Movement – Quartz Seiko Mods
Always check hand size compatibility before buying. Here’s a quick reference:
| Movement | Hour | Minute | Seconds | Subdial |
|---|---|---|---|---|
| NH35/36 | 1.50 | 0.90 | 0.20 | N/A |
| VH31 | 1.20 | 0.70 | 0.17 | N/A |
| VK63 | 1.50 | 0.90 | 0.34 | 0.28 |
Read Listings Carefully
Not all cases are created equal—even if they look similar. Make sure the case is made for your specific movement and confirm fitment of hands, dials, and pushers where applicable.
Final Thoughts from SeikoModder.com
Quartz Seiko mods are growing in popularity—and for good reason. Whether you’re building a clean minimalist three-hander with the VH31 or an eye-catching chronograph with the VK63, quartz mods give you the chance to experiment, learn, and create beautiful custom watches without breaking the bank.
At SeikoModder.com, we’ve tested dozens of parts and suppliers. We recommend:
- VH31 for simple, sweeping-second mods
- VK63 for affordable, eye-catching chronographs—especially since they share hour/minute hand hole sizes with NH-series.
As always, plan your build carefully—especially hand and dial compatibility—and take advantage of AliExpress kits and bundles that are designed to work together.
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