unknownsynthetic
evidence: unknown
no source states which grade this article was bought at — this row exists so 'unknown' stays countable instead of becoming an assumption
exec:seiko-4r36-nh36/unknown
accepteddisputed
movement
Seiko 4R36 / NH36
bounding evidence — no range is drawn on the era axis
not before 1996
Seiko 7S26 · introduced 1996 (sourced)
not before 2006
Seiko 6R15 · introduced 2006 (sourced)
Identity
A caliber is three separate things and this reference keeps them apart: the construction, the names it is sold under, and the article a brand actually bought. A watch model points at an execution — never at a bare construction — which is why “same caliber” is almost never a complete answer.
IDesign — the construction
Seiko 4R36 / NH36
movementproducer: Seiko Instruments Inc. (SII)
IIDesignations — 2 names
| Issuer | Name | Kind | Disambiguated by | Sources |
|---|---|---|---|---|
| Seiko Instruments Inc. (SII) | NH36 | channel | — | |
| Seiko Watch Corporation | 4R36 | house | — |
IIIExecutions — 1 article
No source in this corpus states which grade any Seiko 4R36 / NH36 was bought at. That unknown is stored as a real row rather than left blank, so it can be counted, filtered and excluded from any comparison that would otherwise assume parity.
Specifications
| Property | Value | Scope | Status | Sources |
|---|---|---|---|---|
Jewels build.jewel_count | 24 | — | accepted | |
Date disp.has_date | yes | — | accepted | |
Day disp.has_day | yes | — | accepted | |
Frequency osc.frequency_vph | 21600 vph | — | accepted | |
Power reserve (typical) power.reserve_typical_h | 41 h | — | accepted | |
Introduced prod.intro_year | 2011 | — | accepted |
Lineage
The same relationships as the tree at the top of this page, with their sources. An absence in a column means no source stated one.
Ancestors · 2
Where this construction came from. Read up the arrows.
- Seiko 6R15derived from
- Seiko 7S26derived fromdepth 2
Descendants · 0
What came from it — revisions, variants, clones, licensed copies.
None recorded. An absence here means no source stated one, not that none exists.
Related · 0
Stored in a different table from descent. A successor is not a child.
None recorded. An absence here means no source stated one, not that none exists.
Used by
2
models
2
brands
2
grade unknown
grain 2 model — every record here sits at the same level, so the count is one kind of thing.
- Islander1 modelmodel:islander/islander-38mm-automatic-dive-watch-isl-05
- Nodus1 modelmodel:nodus/sector-pilot
Every brand here is on the strength of a source that names a watch and states this movement. Brands that use this caliber and nobody has sourced yet are absent — this is what has been researched, not what exists.
Sources
- 1Caliber Cornerhttps://calibercorner.com/seiko-caliber-nh36/curated dbtier 2retrieved 2026-08-248 facts on this pagecited, never crawled
- 2namokimods.comhttps://www.namokimods.com/blogs/namokitimes/can-you-build-seiko-mods-with-the-7s26-4r36-or-6r15-calibres-6presstier 3retrieved 2026-08-244 facts on this page
- 3rotatewatches.comhttps://rotatewatches.com/blogs/blog/nh36-watch-movement-specificationspresstier 3retrieved 2026-08-241 fact on this page
- 4watchuseek.comhttps://www.watchuseek.com/threads/seiko-4r36-vs-7s26-major-improvement-or-just-added-hack-hand-wind.937856/forumtier 4retrieved 2026-08-241 fact on this page
- 5Caliber Cornerhttps://calibercorner.com/seiko-caliber-6r15/curated dbtier 2retrieved 2026-08-241 fact on this pagecited, never crawled