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NH Movement Rotor - FPJ Diamond - Blue

The movement, dressed. FPJ Diamond in blue. Seen through the caseback.

A decorated rotor turns the one moving part you see through an exhibition caseback — the weight that swings as you wear the watch — into the finished centrepiece of the movement.

This is a drop-in NH movement rotor — FPJ Diamond, finished in blue by PVD (physical vapour deposition), so the colour is part of the metal's surface, not a layer of paint that can chip or peel.

Swapping it is the simplest mod there is — a single screw, no movement surgery, no watchmaker.

One screw. Two minutes.
You're not opening the movement — just trading the bare oscillating weight for a decorated one.

Seen through the caseback.
The rotor is the first thing the eye lands on behind an exhibition sapphire — the part that moves. Decorate it and the whole movement reads as considered.

PVD, not paint.
The blue is laid down by physical vapour deposition — bonded into the surface, not brushed on. It won't flake, and it can't be stripped back to bare steel.

A two-minute mod.
It seats on the rotor post and holds with a single screw. No movement disassembly, no special tools, no risk to the calibre.

Built for the NH family.
Machined to Seiko's OEM rotor geometry — 0.15mm thicker to carry the CNC decoration — and tested to fit the full NH, 4R and 7S automatic line.

To see it, you'll want

An exhibition caseback. A decorated rotor only shows behind a sapphire (exhibition) caseback — a solid steel caseback hides the movement entirely.

A matching bridge. For the complete look, pair the rotor with a decorated NH movement bridge in the same finish.

  • Finish & Build

    1. Quality Swiss Production Quality, ISO 9001 Certified
    2. Finish FPJ Diamond · Blue · PVD coating
    3. Construction 0.15mm thicker than the Seiko OEM rotor, to carry the CNC decoration

    Compatibility

    1. Fit Movements 7S26, 7S36, 4R15, 4R35, 4R36, 6R15, NE15, NH25, NH26, NH34, NH35, NH36, NH37, NH38, NH39, NH70, NH71, NH72
    2. Caseback Exhibition (sapphire) caseback required to display
  • To allow for CNC decoration, the decorated rotor is 0.15mm thicker than the Seiko OEM rotor. Each rotor is tested to fit all our bridges, cases and casebacks.

    Below is Seiko's technical drawing . As long as the case and caseback follow Seiko's OEM specification — a 0.4mm gap between the rotor and caseback — the rotor fits. If those parts deviate from Seiko OEM dimensions, the rotor may be incompatible.

    SEIKO NH Rotor and Caseback clearance drawing
    1. 1x NH Movement Rotor

    All photos of watches with modification parts are for illustration purposes only and are not included with modification parts purchased.

  • Fitting a rotor is the easiest mod there is:

    1. Unscrew the existing rotor screw with a 2–3mm flat screwdriver and lift the old rotor off.
    2. Seat the decorated rotor on the post.
    3. Screw it back down — done.

    New to modding? Start with Seiko Modding: The Complete Build Guide , or browse NH Movements to build around it.

Questions, Answered

Everything worth knowing before you build.

Will a decorated rotor fit my movement?

Yes — it fits the full Seiko NH automatic family and its relatives: 7S26, 7S36, 4R15/35/36, 6R15, NE15, NH25/26, NH34, NH35, NH36, NH37, NH38, NH39, and the NH70/71/72 skeletons. The rotor screws onto the standard rotor post. What matters is caseback clearance: as long as the case and caseback follow Seiko's OEM specification — a 0.4mm gap between rotor and caseback — it fits. Non-OEM parts with tighter clearance may not.

Do I need an exhibition caseback to see the rotor?

Yes. A decorated rotor is only visible through a sapphire (exhibition) caseback. A solid steel caseback covers the movement entirely, so the decoration behind it would never be seen — if your build uses a solid caseback, a decorated rotor won't show.

Is the finish paint? Will it wear off?

It isn't paint — it's PVD (physical vapour deposition), bonded into the metal's surface. It won't chip or peel the way a painted coat would, and it can't be stripped back to bare steel; abrasive attempts only ruin the part. Treat the colour as permanent.

Why is the decorated rotor slightly thicker than a stock Seiko rotor?

By 0.15mm. That extra material is what lets the decoration be CNC-machined into the face. Every rotor is tested to fit our cases, bridges and casebacks, and the small increase stays within Seiko's OEM clearance.

Is fitting a decorated rotor difficult?

No — it's the easiest Seiko mod there is. Unscrew the single rotor screw, lift off the old rotor, seat the decorated one, and screw it back down. There's no movement disassembly and no watchmaker required.

Customers praised this NH movement rotor for its "flawless pattern" and "gorgeous" blue finish. Shoppers found installation "very easy" and appreciated the excellent quality that "highlights the movement well with a display case back." The deep smoky blue shade and diamond texture add a custom, premium look to watch builds. All reviews were 5-star ratings.

  • The pattern is flawless. The bluing is gorgeous.
  • The rotor arrived quickly and it is of the highest quality.
  • Very easy mod and really highlights the movement well with a display case back.
Blue (positive)Pattern (positive)Bluing (positive)Quality (positive)Build (positive)
  • 5 stars: 7 (100%)
  • 4 stars: 0 (0%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
B
Brandon C. (Menasha, US)
Using this mod part for: 36mm dressy style case
Perfect!

The pattern is flawless. The bluing is gorgeous. It's going to complete the build for sure.

E
Eric W. (McKinney, US)
Using this mod part for: Aftermarket Explorer style case.
Excellent quality!

Chose this rotor for a silver and blue dress build on an NH35 movement. This was my first rotor swap. Very easy mod and really highlights the movement well with a display case back.

O
O.
Using this mod part for: SKX007 Samurai Conversion
Matches my build perfectly

Lovely deep smoky blue shade and the textures pair well with the other textured blue elements of my build

N
Nathan T. (Oceanside, US)
Using this mod part for: Seiko 5 7S26
Looks amazing

The rotor arrived quickly and it is of the highest quality. Went in very easily and looks fantastic. Couldn't have asked for better.

L
Louis W. (Louisville, US)
Using this mod part for: NAMOKI custom pilot case
Awesome rotor

Beautiful rotor adds that custom look to any watch

C
CJ A. (Pittsburgh, US)
Using this mod part for: Seikonaut
Great communication and great service

Ariel, Thank you so much for answering my questions and putting my mind at ease purchasing my first modded watch. I just received my order today and it looks way better in person than what I saw in the pictures!

Will definitely leverage this site again for future mods!

D
Drewe M. (Canberra, AU)
Blue custom rotor

The nicest rotor I have put on a watch yet, many thanks 😊

T
Tom

Can i custom my name on it instead of "japan movement..."?

Adriel from LuciusAtelier.com

Hi Tung,

Thanks for expressing interest in our mod parts!

Sorry, customization like that isn’t possible. All rotors are pre-engraved and manufactured in batches, so we’re unable to modify individual pieces.

Let me know if you have any other questions!

Best regards,
Adriel
Lucius Atelier | SEIKO Mod Parts

J
Justin S.

Will this rotor paired with one of your custom bridges fit while using your SKX Slim Solid Caseback?

Adriel from LuciusAtelier.com

Hello Justin!

Thanks for expressing interest in our mod parts!

Yes, it will fit. However, if you can't see the decorated movement while adding weight to your timepiece, it would not be a fruitful mod.

Hope this helps. Let me know if you have any more questions.

Cheers,
Adriel