NH71.5 Custom Watch Movement: Build Guide & Alternatives (2026)

The NH71.5 is a modified version of the NH71 skeleton movement — a custom workaround created by the modding community to get specific characteristics not available from any single stock Seiko movement. This guide explains what it is, why builders create it, and how you can build one yourself.

What Is the NH71.5 Movement?

The "NH71.5" isn't an official Seiko caliber — it's a community nickname for a hybrid skeleton movement. Builders create it by combining components from two different NH movements to achieve a specific set of features:

• Skeleton rotor visibility (from NH71)
• Hacking seconds (from NH71)
• Specific bridge finishing or rotor weight (varies by builder)

The name "71.5" suggests it sits between the NH71 and NH72 in terms of features — a custom combination not available off the shelf.

Why Build with an NH71.5?

For most builders, the standard NH72 ($95) is the recommended skeleton movement — it includes hacking, hand-winding, and excellent open-work visibility. However, some builders prefer the NH71.5 approach for specific aesthetic or functional reasons.

If you're new to skeleton builds, we recommend starting with the standard NH72 skeleton movement — it offers the best feature set without requiring any modification. See our NH72 Skeleton Movement Guide for details.

NH71.5 vs Other Skeleton Movements

Our recommendation: Unless you have a specific reason for building an NH71.5, the NH72 gives you more features at the same price point.

Parts You Need

To build a complete skeleton watch with any NH7x movement, you need:

• Skeleton movement — NH72 ($95) recommended, or NH71 ($95) / NH70 ($70)
• Skeleton dial — Royal Oak Skeleton 28.5mm ($40) or 30.8mm ($39)
• Case with display caseback — Royal Oak 37mm ($149) or Seikonaut 40mm ($149)
• Hands — Royal Oak Hands V2 ($28)

Build Steps

1. Remove the stem from the skeleton movement
2. Attach the skeleton dial — align feet with movement receiving holes
3. Install hands using a hand press (hour → minute → seconds)
4. Place chapter ring in the case
5. Insert the movement assembly into the case
6. Attach the stem and crown
7. Screw on the display caseback (grease the gasket first)
8. Test winding, hacking, and hand alignment

For a detailed walkthrough, see our complete build guide.

Frequently Asked Questions

Read More

• NH72 Skeleton Movement Guide
• Build Your Own Custom Seiko Watch
• 37mm Royal Oak Case Guide
• 28.5mm vs 30.8mm Seiko Dials
• Shop All Movements
• Browse Prebuilt Skeleton Mods

Nomods is not affiliated with Seiko. All watches are independently built using Seiko-compatible movements and aftermarket components.