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SKX013 Diver 38 Black Ultra Thin Edition — side profile showing 10.86mm ultra-thin case thickness

Ultra Thin Edition
Seikonaut Bracelet 20/16mm [TITANIUM] - - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts

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  • SKX013 Diver 38 Black Ultra Thin Edition — side profile showing 10.86mm ultra-thin case thickness

    Ultra Thin Edition
  • Seikonaut Bracelet 20/16mm [TITANIUM] - - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts

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    Home / All Products / Bauhaus 33mm — Ultra Thin Watch Case
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    Bauhaus Watch Case - 33mm [ULTRA THIN EDITION] - Solid - - - Lucius Atelier - Swiss Quality Seiko Watch Mod Parts
    New

    Bauhaus 33mm — Ultra Thin Watch Case

    $145 SGD - $170 SGD
    Caseback
    Worldwide
    Delivery         Express
    2–4 Days         Replies In
    1 Day         30-Day
    Returns

    Bauhaus Watch Case 33mm Ultra Thin in polished steel

    Minimalist Elegance. Ultra Thin. Unprecedented Size.

    The Bauhaus Watch Case 33mm, part of our Ultra Thin Edition series, is engineered for the purist — the first, smallest, and thinnest NH-compatible watch case on the market today. A groundbreaking foundation for a custom dress build, with nothing on it that doesn't need to be there.

    The Bauhaus design language is built on a single century-old idea: form follows function. Clean lines, pure geometry, an uncompromised focus on minimalism. This case captures that spirit exactly — a 33mm canvas of elegant, mid-century proportions, slipping effortlessly under a dress shirt cuff.

    Achieving this profile around the robust NH caliber pushed the engineering hard. The result is sub-10mm in solid 316L stainless steel with a sleek polished finish — proportions most NH-compatible cases simply can't reach.

    Sapphire pre-installed. Crown included. Ready to build.
    The flat sapphire crystal ships pre-installed and aligned at our workshop, and the 6mm coin-edge crown is in the box. You add the dial, hands, chapter ring and movement — and you have a complete dress watch. A foundation that's genuinely yours, down to the millimetre.

    The smallest of the line.
    33mm diameter, 41.5mm lug-to-lug, 18mm lug width. The most compact case we make — a beautifully understated wrist presence, and the truest mid-century dress proportion in the Ultra Thin family.

    Genuinely thin.
    9.93mm with the solid caseback, measured on a vernier caliper. The engineering behind that number: a standard NH movement is 7.59mm tall on its own — which leaves barely 2.3mm for the crystal, caseback floor, walls and hand clearance combined. The thinnest case in our Ultra Thin line.

    Form follows function.
    No fluting, no bezel detailing, no imposed character — the Bauhaus is deliberately the most neutral foundation we build. Crafted from robust 316L stainless steel with a clean polished finish, it's pure geometry and nothing else.

    A blank canvas for the purist.
    The visible bezel is just 1.4mm — barely a frame. On this case the dial isn't a component, it's the entire statement. Whatever dial and hands you choose carry 100% of the design. Build accordingly.

    Caseback Total Thickness Water Resistance Best for
    Solid · HEADLINE BUILD 9.93mm 100m / 10 ATM The thinnest profile — daily and formal wear
    Sapphire 10.9mm 100m / 10 ATM Movement display — show off the rotor

    The solid caseback is the headline build — this is the case at its slimmest, sub-10mm. The sapphire caseback adds slight thickness in exchange for a view of the NH movement.

    Heads up — sold separately

    Chapter ring. This case requires a SKX013-spec chapter ring to seat the dial correctly — without it, the dial sits too low and hands won't clear. The case fits both normal and ultra thin chapter rings; the choice depends on your dial, not the case. If your dial has applied (raised) indices, choose ultra thin for clearance. If flat-printed, either works. When in doubt, ultra thin is the safer default. Browse compatible chapter rings .

    The crown, caseback and sapphire crystal are all included with this case. You only need a dial, hands, chapter ring and movement to complete the watch.

    For experienced modders only — TYPE M movements only

    This case fits TYPE M versions of NH35, NH36, NH38, NH70, NH71, NH72 only. TYPE L will NOT fit. Due to tight clearance between hands and sapphire, this case is recommended only for professional watchmakers and experienced modders.

    • Dimensions

      1. Case Diameter 33mm
      2. Case Thickness 9.93mm (Solid Caseback) / 10.9mm (Sapphire Caseback)
      3. Lug to Lug 41.5mm
      4. Lug Width 18mm
      5. Visible Bezel 1.4mm

      Materials & Finish

      1. Quality Swiss Production Quality, ISO 9001 Certified
      2. Case Material 316L Stainless Steel
      3. Case Finishing Polished
      4. Crown 6mm coin-edge, screw-down (included)
      5. Crystal Flat sapphire with clear anti-reflective coating
      6. Crystal Size 29.5mm x 1mm

      Compatibility

      1. Movements TYPE M: NH35, NH36, NH38, NH70, NH71, NH72
      2. Dials 28.5mm
      3. Chapter Rings SKX013-spec (required, sold separately)
      4. Hands NH movement compatible

      Water Resistance

      1. Solid & Sapphire Caseback 100m / 10 ATM

    • New to Seiko modding? Here's everything you'll need for a complete, functioning watch — in the order you'd actually assemble it.

      What's already in this purchase:

      The case body with pre-installed flat sapphire crystal, the 6mm coin-edge crown, and your chosen caseback. That's the foundation. Everything below is what you'll add to make a wrist-ready watch.

      The 4 parts you'll need for a complete watch:

      1. Chapter ring — required first. The chapter ring seats the dial at the correct height; without it, the dial sits too low and the hands won't clear.
        (SKX013-spec — sold on a separate page. See the "sold separately" panel above for normal vs ultra thin guidance.)
        Browse compatible chapter rings
      2. Dial (28.5mm) — the face of the watch, and on this case, the entire statement. The biggest aesthetic choice you'll make. Match it to your chosen movement (date / day+date / no-date dial).
      3. Hands — paired with your dial. Most modders match lume colour across both hands and dial markers (BGW9 white-blue, C3 green, etc.).
      4. Movement — NH35 (date), NH36 (day+date), NH38 (no date), or source your own. The movement is the engine of the watch.

      Optional finishing touches:

      1. Decorated bridge + rotor (only visible with sapphire caseback) — replace the stock NH movement bridge and rotor with our Côtes de Genève decorated set, viewable through the sapphire caseback. Note: our bridges fit only our rotors (not OEM Seiko rotors), so they're chosen as a pair. Recommended for experienced modders only — or tick Assemble Watch below and we'll handle it.

      Want it built for you?

      Tick the Assemble Watch (+SGD $50) option above on this page and we'll handle the full build in our Singapore workshop — case fitting, movement seating, crown alignment, caseback press and function check.

      Heads up: assembled watches require 2–5 business days of workshop time before shipping.

      Once your parts arrive, see the How To Mod tab for assembly tutorials.

      1. 1x Watch Case Body (with pre-installed flat sapphire crystal)
      2. 1x Crown — 6mm coin-edge, screw-down
      3. 1x NH Caseback (Solid or Sapphire, per selection)

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

      1. A Complete Guide On How To Mod Your SEIKO Watch Dial And Hands (Photos & Video)
      2. Fitting dials with four dial legs
      3. Seiko Modding: The Complete Build Guide (2026)

    Questions, Answered

    Everything worth knowing before you build.

    Just how thin is it?

    9.93mm with the solid caseback, measured on a vernier caliper — under 10mm. A standard NH movement is 7.59mm tall on its own, so the crystal, caseback floor, walls and hand clearance share just over 2mm between them. It's the thinnest case in our Ultra Thin line.

    What comes in the box — do I need to buy a crown?

    No. The Bauhaus 33 ships with the 6mm coin-edge screw-down crown, the caseback (Solid or Sapphire, per your selection), and a pre-installed flat sapphire crystal. To finish the watch you only need a dial, hands, chapter ring and movement.

    Why is the bezel so thin?

    By design. The visible bezel is only 1.4mm — the Bauhaus is built to get out of the way so the dial carries the whole look. If you want the case to frame the dial, this isn't the one; if you want the dial to be the watch, it's exactly the one.

    What's the difference between Type M and Type L?

    Type M and Type L are Seiko's two factory hand-fitting versions of the NH series. Type L sits higher than Type M — about 0.4mm taller from base to second-hand pinion. Because of the tight clearance between hands and sapphire in Ultra Thin Edition cases, only Type M will fit. Confirm your movement type before ordering.

    Do I need to remove the sapphire crystal to install the chapter ring?

    No — and that's the whole point of us pre-installing the sapphire for you. The chapter ring sits on top of the dial inside the case, not under the crystal, so the crystal stays where it is throughout the build. (If you ever do need to remove the sapphire — for example, to replace it — that's a workshop job we handle for you, not an at-home step.)

    Should I choose the normal or the ultra thin chapter ring?

    The choice depends on your dial, not the case — both sizes fit every Ultra Thin Edition case. If your dial has applied (raised) indices, the ultra thin chapter ring is the better choice because its slimmer profile gives the indices clearance instead of resting on top of them. If your dial is flat-printed (no applied markers), either size works. When in doubt, the ultra thin chapter ring is the safer default because it works with both dial types.

    What is an SKX013 chapter ring and why does it matter?

    A specific size and spec used by Seiko in the SKX013 (discontinued 2019). The LA smaller-case lineup all uses this same spec, which means dozens of chapter ring designs work across every smaller case in the catalogue.

    Will SKX007 dials fit?

    Any 28.5mm dial will fit. Stock SKX007 dials may seat differently because the original SKX007 has a 4 o'clock crown position with offset dial feet, while Ultra Thin Edition cases are designed for 3 o'clock dial feet.

    Does this case need a chapter ring?

    Yes — every Ultra Thin Edition case requires an SKX013-spec chapter ring, sold separately. The chapter ring seats the dial at the correct height; without it, the dial drops and the hands will not clear properly.

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