Everyone remembers their first Seiko mod. That moment when the back case finally clicks into place, and you realize — this isn’t just a watch anymore. It’s yours.
If you’re here, you’ve probably fallen into the same rabbit hole as thousands of builders before you. Maybe you’ve seen those gorgeous custom SKX builds on Instagram. Maybe you bought a Seiko 5 and thought, “What if I change just one thing?”
Welcome to the world of Seiko modding — where one simple change turns into a full-blown obsession. Let’s make sure your first project doesn’t end with broken hands or scratched dials.
1. What Is Watch Modding (and Why Seiko?)
Modding is short for “modifying” — customizing your watch to look, feel, and perform exactly how you want. You can swap the dial, hands, bezel, or even the movement itself.
Seiko watches are the perfect starting point because:
- They use modular parts — many components fit across models.
- The NH35 movement is reliable, easy to service, and beginner-friendly.
- Aftermarket parts are everywhere — and affordable.
- You can build something unique without needing a watchmaker’s certification.
If you’ve never opened a watch before, don’t worry — every expert once trembled holding their first case opener.
2. What You’ll Need (and Why Each Item Matters)
Before we talk about tools and parts, let’s clear something up: Modding isn’t about buying everything at once — it’s about understanding what each piece does and how it connects to your vision.
We’ll go through three layers of gear: Essentials, Precision Tools, and Optional Upgrades — each one fits a purpose.
A. Essential Tools for Every Beginner
These are non-negotiable for any DIY builder or watch modder:
| Tool | Purpose | Tip |
|---|---|---|
| Case Back Opener | To open the watch case safely | Use a 3-point adjustable wrench for screw-down backs |
| Case Holder | Keeps the watch from slipping | Rubber pads prevent scratches |
| Spring Bar Tool | Removes straps or bracelets | Essential before opening your watch |
| Hand Remover Tool | Lifts hands without bending them | Always use a dial protector underneath |
| Hand Setter Tool | Presses new hands onto the posts | Use nylon tips for NH35 movements |
| Movement Holder | Keeps movement stable during work | Prevents hand slippage and dust contamination |
| Tweezers (Plastic or Brass) | Handle small screws safely | Never use magnetic tweezers near balance wheels |
| Dust Blower & Rodico Putty | Cleans dial and crystal | Prevent dust under your new dial |
| Loupe or Magnifier Lamp | Essential for visibility | 5x–10x magnification is ideal |
You can get all these in a beginner’s Watchmaker Toolkit or as a set from Sugargoo’s Watch Repair Tools collection — perfect for NH35 modding.
B. Precision Tools for Advanced Accuracy
Once you’ve done your first build, you’ll want more precision — and that’s where these come in.
| Tool | Purpose | Why You’ll Love It |
|---|---|---|
| Timegrapher | Measures movement accuracy | Shows rate, amplitude, and beat error instantly |
| Demagnetizer | Fixes time drift from magnetism | Especially useful for Seiko NH35 builds |
| Case Press | Installs crystals and case backs evenly | No cracked crystals ever again |
| Pin Punch Set | Removes bracelet links cleanly | Ideal for resizing stainless steel bracelets |
| Polishing Cloths | Keeps cases scratch-free | Use after every mod session |
These tools turn frustration into fun. When you realize you can align a second hand within 0.1mm — that’s the moment you become hooked.
🧩 C. Optional Upgrades for Perfectionists
You don’t need these for daily care. But once you start assembling full custom builds or tuning movements, they become essential.
| Tool | Purpose |
|---|---|
| Ultrasonic Cleaner | Deep cleans bracelets and crowns |
| Watch Press Dies | For installing domed sapphire crystals |
| LED Magnifier Station | Both hands free for fine work |
| Anti-static Work Mat | Prevents dust and parts loss |
| Precision Screwdrivers | For NH35 keyless works or crown assemblies |
Every small upgrade gives you more control, fewer mistakes, and cleaner builds until it feels new.
4. Setting Up Your Workspace
Your workbench doesn’t need to look like a Swiss atelier — just clean, bright, and organized.
Here’s how to set up a simple modding station:
- Bright, diffused light — never direct.
- A lint-free cloth for movement handling.
- Separate trays for hands, screws, and gaskets.
- Small tweezers for small parts.
- Gloves, or clean hands and calm breath.
The watch doesn’t care about how skilled you are — it cares about how present you are.
5. The Mental Side of Modding: Patience Is the Real Tool
Ask any seasoned modder what broke their first time. They’ll say: “My nerves.”
The truth is, watch modding is 50% precision, 50% patience. If something feels stuck, stop. Walk away. Come back later.
Here’s a mindset that helps: You’re not fixing time. You’re learning how to control it — one gear, one hand, one dial at a time.
Take photos at every step. It helps you reassemble — and later, it becomes your modding diary.
6. Common Mistakes First-Time Modders Make
| Mistake | Why It Happens | How to Fix |
|---|---|---|
| Installing hands at the wrong time | Setting not at midnight | Always set date to 12 AM first |
| Forcing dial feet | Wrong hole spacing | Test fit before tightening screws |
| Using wrong crown stem | Mismatch length | Measure case depth first |
| Buying fake NH35 | Non-verified sellers | Use Sugargoo verified stores |
| Oiling without tools | Over-lubrication | Use only one drop on escapement pivots |
Mistakes happen. Every scratch is a teacher — but fewer scratches mean faster progress.
7. Where to Buy Trusted Seiko Modding Parts
You can’t build a great watch from random eBay listings. That’s why serious builders use Sugargoo — the verified Taobao agent for watch parts and accessories.
Sugargoo gives you:
- Direct access to NH35 parts, dials, hands, and cases
- Real QC photos before shipping
- Combined orders (movement + case + dial = one box)
- Reliable communication with Taobao/1688 sellers
It’s like having a local supplier in China — without the language barrier.
If you’re just starting, browse:
You’ll find everything your first build needs — and more ideas for your second.
8. From Builder to Creator
Once you’ve finished your first Seiko mod, something changes. You’ll never look at watches the same way again.
You’ll start noticing crown knurling, hand height, crystal reflection. You’ll start saying this sometimes “I might just swap the bezel” — and three hours later, you’ve disassembled the entire watch.
That’s the beauty of modding: it’s not just about watches, it’s about mastering patience, precision, and personality.
9. Next Steps: Keep Building, Keep Learning
You’ve made it this far — now keep going. Here’s where to continue your learning:
- DIY Watch Assembly for Beginners
- Everything You Need to Start Watch Modding
- How to Replace a Watch Dial Without Damaging the Hands
- The Art of Modding: Building a Watch from Scratch
Each article connects to another step in your watchmaking journey — from hobbyist to craftsman.
10. Final Thoughts: It Starts With One Build
Your first Seiko mod will test your patience. It’ll humble you, frustrate you, and then — if you stick with it — reward you more than any factory watch ever could.
Because when you’ve seen your NH35 movement ticking behind the sapphire case back, knowing you assembled every piece, that’s not just satisfaction. That’s craftsmanship.
And that’s where the real addiction begins.