Family line
Grand Seiko 9S55
Based-on star (WatchBase sense)5 calibers4 lineage edges1 related edgesdesign:grand-seiko-9s55compare specs · 5
This profile traverses clone_of · derived_from · ebauche_of · revision_of · variant_of and keeps disputed edges. Every edge in this view carries at least one reference.
Same caliber, other senses of “family”Everything (debug) · 5 calibersHeritage · 5 calibersParts cluster (Jules Borel sense) · 1 calibersManufacturer-internal (Ranfft sense) · 1 calibers
Edge types in this family
accepteddisputedcontested region
Generations run left to right, ancestors first, and the axis along the top is ordinal rather than linear: each band is one generation, labelled with the range of sourced introduction years it contains. A band reads “—” when no caliber in it has a year anyone published — the gap is the finding, not a rendering failure. Dotted arcs above and below the drawing are related edges — successor, drop-in, no-derivation — which are stored in a different table from lineage and can never form part of an ancestry path.
Every edge in this view
| Caliber | Relationship | To | Status | Detail | Sources |
|---|---|---|---|---|---|
| Grand Seiko 9S65 | derived from lineage | Grand Seiko 9S55 | accepted | interchange note: Grand Seiko names two changes against the 9S55: the winding transmission goes Magic Lever → hardened reverser gear train, and the escapement is produced by MEMS. Nothing in either source addresses parts interchange. · component delta: automatic_module,escape_wheel_treatment | |
| Grand Seiko 9S66 | derived from lineage | Grand Seiko 9S65 | accepted | interchange note: Same rate, reserve, frequency and jewel count as the 9S65; the delta named by the maker is the GMT hand and its independent hour setting. · component delta: complication_module | |
| Seiko 8L35 | derived from lineage | Grand Seiko 9S55 | accepted | interchange note: The two published deltas are adjustment (+15/−10 s/d against the Grand Seiko Standard’s +5/−3) and finishing. No component swap is named anywhere read this round. · component delta: decoration,regulation_method | |
| Seiko 8L45 | derived from lineage | Grand Seiko 9S65 | accepted | interchange note: Same jewel count, same dimensions and same 72 h reserve as the 9S65 by the source’s own statement; the published deltas are the rate window (+10/−5 s/d against the Grand Seiko Standard’s +5/−3) and the finishing, described as "broad stripes on the plates, bridges and rotor". · component delta: regulation_method,decoration | |
| Seiko 8L45 | successor of related | Seiko 8L35 | accepted | The 8L45 does NOT descend from the 8L35 — the sources are explicit that the two do not share specs or jewel count, and that the 8L45 comes from the 9S65 while the 8L35 comes from the 9S55. This is commercial replacement inside Seiko’s own range, which is why it is a related edge and can never appear in an ancestry path. |
Sources
- 1grand-seiko.comhttps://www.grand-seiko.com/us-en/collections/movement/mechanical/9s65manufacturertier 1retrieved 2026-08-241 fact on this page
- 2Monochrome Watcheshttps://monochrome-watches.com/grand-seiko-60th-anniversary-limited-edition-sbgr321/presstier 2retrieved 2026-08-241 fact on this page
- 3grand-seiko.comhttps://www.grand-seiko.com/us-en/collections/movement/mechanical/9s66manufacturertier 1retrieved 2026-08-241 fact on this page
- 4Monochrome Watcheshttps://monochrome-watches.com/introducing-seiko-prospex-sla071-landmaster-30th-anniversary-limited-edition-specs-price/presstier 2retrieved 2026-08-241 fact on this page
- 5Monochrome Watcheshttps://monochrome-watches.com/review-king-seiko-vanac-sla083-sla085-sla087-sla089-sla091-8l45-grand-seiko-movement-8l45-price/presstier 2retrieved 2026-08-242 facts on this page
- 6Monochrome Watcheshttps://monochrome-watches.com/seiko-prospex-marinemaster-professional-titanium-sla081-limited-edition-60th-anniversary-seiko-first-dive-watch-review-price/presstier 2retrieved 2026-08-242 facts on this page