Seiko NH38 (TMI NH38A) caliber vs Seiko VH31 (SII) caliber: specs compared
Updated 05 September 2026.
11
specs differ
Seiko NH38 (TMI NH38A) caliber and Seiko VH31 (SII) caliber differ on 11 specs: maker, size, casing diameter, movement height, frequency, jewels.
| Spec | Seiko NH38 (TMI NH38A) caliber | Seiko VH31 (SII) caliber |
|---|---|---|
| Maker | Seiko Instruments / Time Module (TMI) | Seiko Instruments / SII |
| Size | 12 ligne | 10 1/2 ligne |
| Casing diameter | 27.40 mm | 23.30 mm |
| Movement height | 5.32 mm | 3.45 mm |
| Frequency | 21,600 A/h (3 Hz) | 32,768 Hz quartz |
| Jewels | 24 | 0 |
| Winding | automatic, bidirectional, hacking and hand-wind | quartz, battery 371 (SR920SW) |
| Calendar / layout | centre seconds, open heart, no date | centre sweeping seconds, no date, hacking |
| Hand fitting | hour 1.50 / minute 0.90 / second 0.20 mm (bore) | hour / minute / sweeping second |
| Stem | NH38 stem | VH31 stem |
| Power reserve | more than 41 h | battery, up to 2 years |
Questions and answers
How do Seiko NH38 (TMI NH38A) caliber and Seiko VH31 (SII) caliber compare?
Seiko NH38 (TMI NH38A) caliber and Seiko VH31 (SII) caliber differ on 11 specs: maker, size, casing diameter, movement height, frequency, jewels.