Movement comparison
NH35 vs Miyota 8215
about 1.46 mm narrower; 0.35 mm taller. Can Miyota 8215 replace NH35? Only with changes to the watch or parts. Some fit figures are still unpublished, so this verdict is not confirmed.
Sources checked · How we source numbers
Published figures
Differences are highlighted. Each number links to its source; an empty field says what is missing.
| Figure | ATMI NH35 | BMiyota 8215 |
|---|---|---|
| Diameterone side only | 27.4 mm1 | not published by Miyota |
| Casing diameterdiffers | 29.36 mm1 | 25.6 mm2 |
| Size in lignesdiffers | 12‴3 | 11½‴4 |
| Heightdiffers | 5.32 mm1 | 5.67 mm4 |
| Jewelsdiffers | 243 | 214 |
| Beat rate | 21,600 bph3 | 21,600 bph4 |
| Power reservediffers | 41 h6 | 42 h4 |
| Accuracy (maker) | −20 to +40 s/day6 | −20 to +40 s/day4 |
| Lift anglediffers | 53°6 | 49°7 |
| Hands and functions | hours, minutes, centre seconds, date3 | hours, minutes, centre seconds, date4 |
| Hacking seconds | Yes3 | Yes4 |
| Hand winding | Yes6 | Yes4 |
| Date windowdiffers | 3H6 · 3H, 6H, 9H8 | 3H, 6H4 · 3H2 |
| Do not set the datediffers | 21:00–04:009 | 21:00–01:007 |
| Crown | 3H6 | 3H4 |
| Hand holesone side only | hour 1.5 · minute 0.88 · second 0.198 mm8 | only in Miyota’s drawing; not read yet |
| Dial feetdiffers | 1:36, 7:338 · 1:36, 7:338 | 5:39, 10:482 · 5:39, 10:482 |
| Dial centre holediffers | 2.05 mm8 | 2 mm2 |
Can Miyota 8215 replace NH35?
The direction matters: this checks a watch built for the first calibre with the second installed. Size alone does not prove that hands, dial, stem and case will fit.
Fits with changes· not confirmed
- ≠diameterMiyota 8215 is about 1.46 mm narrower (25.94 mm vs 27.4 mm, from the size in lignes): it needs a movement ring or holder to sit centred.
- ≠heightMiyota 8215 is 0.35 mm taller (5.67 mm vs 5.32 mm): check the room under the crystal and the case back; the hands sit higher.
- ≠dateDate at 3H on both, but the window centre is 10.125 mm from the axis vs 10.55 mm: a dial cut for one will not line up with the other.
- =crownCrown at 3H on both.
- ≠dial feetDial feet at 5:39, 10:48 vs 1:36, 7:33: cut the feet and fix the dial with dots, or use a dial made for Miyota 8215.
Not published, so not checked: a millimetre diameter for Miyota 8215; hand holes for Miyota 8215.
Check the actual case, stem height and parts before ordering. Compare another pair.
Sources
Documents checked · Report a wrong number
- 1Time Module Ltd. — Watch Movement Specification and Drawing - Standard Mechanical Movement NH35A · pdf · read
- 2Citizen Watch / Miyota — CAL.8215 Drawing (p.1 Frame for Case 8215001, p.2 Indications for Dial 8215-33E, p.3 Setting Stem 065-212, p.4 Casing Holder 500-710) · pdf · read
- 3Time Module Ltd. — Product Line-Up - Mechanical (NH0&NH3); NH34/NH35/NH36 product blocks · html · read
- 4Citizen Watch Co., Ltd. (MIYOTA) — MIYOTA movement 8215 product page · html · read
- 5Citizen Watch Co., Ltd. (MIYOTA) — MIYOTA movement overview (catalogue table, 2 pages) · pdf · read
- 6Time Module Ltd. — Technical Guide & Parts Catalogue, Cal.NH3 Series (NH34A/35A/36A/37A/38A/39A) - Automatic Mechanical · pdf · read
- 7Citizen Watch Co., Ltd. (MIYOTA) — CAL.8215 Spec. sheet · pdf · read
- 8Time Module Ltd. — Watch Movement Specification and Drawing - NH35A (drawing pages read: Appearance-1, Hand Fitting, Hand Setting Stem, Dial-1, Dial-2, Hands) · pdf · read
- 9Time Module Ltd. — Operation Manual, Cal.NH3 Series (NH34A/35A/36A/37A/38A/39A) · pdf · read
- 10Citizen Watch Co., Ltd. (MIYOTA) — CAL.8215 Instruction manual · pdf · read