Watch Movements

Watch Movements

Watch Movements: The Heart of Seiko Modding

Explore Seiko Movements for Modding

Discover reliable Seiko movements like the NH35, NH34, and NH72. Perfect for Seiko Mods, these automatic movements deliver precision and durability.

Enhance Your Custom Watch Design

Choose from versatile watch movements, including stunning skeleton movements, to elevate your watch modding projects.

FAQs — Seiko Mod Movements

Which movements are most common in Seiko mods?
The **NH35** (date) and **NH36** (day-date) are the most widely used. They’re reliable, affordable, and supported across nearly all mod cases, dials, and hands.
What’s the difference between NH35 and NH36?
Both are automatic hacking and hand-winding movements. **NH35** has a single date complication; **NH36** includes both day and date. Dimensions and hand sizes are otherwise the same.
Are NH movements compatible with SKX and 5KX cases?
Yes. Most SKX/5KX-style cases are designed for NH35/NH36 without modification. Always check case fit notes for crown stem alignment and movement holder compatibility.
Do I need special hands for NH35/NH36?
Yes, hands must match Seiko NH pinion sizes: **hour 1.50 mm, minute 0.90 mm, seconds 0.25 mm**. All hands listed in our store specify compatibility.
Can I swap between NH and Seiko 7S/4R movements?
Yes in most cases. NH35/NH36 are derived from Seiko 4R35/4R36 and share dimensions. Many parts are cross-compatible, though hand-winding and hacking features differ.
What about skeleton or NH7x series movements?
Some **Royal Oak** and **skeleton builds** support NH7x series. These have the same dimensions but may need dials with open windows. Always verify fit notes before mixing.
Do movements come regulated?
Factory NH movements are usually within **±20–40 seconds/day**. We recommend regulating for tighter accuracy during your build. Most modders adjust them down to ±5–10 seconds/day.
What tools do I need to install a movement?
At minimum: a caseback opener, movement holder, hand-setting tools, tweezers, and blower. Optional but recommended: timegrapher for regulation and proper lubricants for servicing.

Blog posts

View all
Example blog post
Example blog post
Example blog post