Compatibility reference
NH35 Movement Dimensions
The NH35's own footprint, not the dial or case it goes into: outer diameter, height, and the dial and hand sizes it's built to accept.
NH35 dimensions at a glance
| Movement outer diameter | 27.40mm |
|---|---|
| Movement height | 5.32mm (without crown) |
| Compatible dial diameter | 28.4-28.5mm |
| Hour hand tube | ~1.50mm |
| Minute hand tube | ~0.90mm |
| Seconds hand tube | ~0.20mm |
The 27.40mm outer diameter is the movement itself; the 28.4-28.5mm figure is the dial diameter the movement is designed to sit under. Case internal depth also needs to clear the full movement + dial + hand + crystal stack, typically at least 12-13mm.
NH36a vs NH35: what the names mean
NH36a and NH36 are the same movement. The "A" is the variant letter in the official Seiko SII caliber code, exactly as the NH35 is properly the NH35A. So there is nothing to choose between an NH36 and an NH36a. The real decision is NH35 versus NH36, and that comes down to one thing: whether you want a day display alongside the date.
| Specification | NH35 | NH36 |
|---|---|---|
| Full caliber code | NH35A | NH36A |
| Display | Date only | Day and date |
| Outer diameter | 27.40mm | 27.40mm |
| Height (no crown) | 5.32mm | 5.32mm |
| Dial diameter | 28.4-28.5mm | 28.4-28.5mm |
| Dial cutout needed | Date window | Day and date aperture |
Because the footprint is identical, a case, hand set, or crystal that suits an NH35 also suits an NH36, and both take the same hand tube sizes. The dial is the part that has to change: an NH36 needs a dial cut for the day and date aperture. See NH36 Compatible Dials for the fit check.
Check your case against these dimensions
Dimensions are only half the fit check. Use the builder to combine an NH35 with a case, dial, and hands, and review the compatibility warnings before ordering parts.
Check your build in the free builder →Common questions
- What size is the NH35 movement?
- The NH35 movement has an outer diameter of 27.40mm and a height of 5.32mm (without the crown). It accepts dials around 28.4-28.5mm and hands sized roughly 1.50mm (hour), 0.90mm (minute), and 0.20mm (seconds).
- Is the NH36a the same as the NH36?
- Yes. NH36A is the full caliber designation; the trailing A is the variant letter Seiko SII uses, the same as NH35A for the NH35. There is no separate NH36a movement.
- What is the difference between the NH36a and the NH35?
- The NH36A (NH36) adds a day display alongside the date; the NH35 shows the date only. Both share the 27.40mm outer diameter, 5.32mm height, and the same dial and hand tube sizes, so the dial is the part that has to match.
- Does the NH36 fit the same cases as the NH35?
- Yes. The footprint is identical, so a case that takes an NH35 takes an NH36. Only the dial needs to be cut for the day and date aperture.