Skip to content
WatchtheDetails

Movement comparison

NH35 vs 4R35

same diameter; same height. Can 4R35 replace NH35? The known figures match. Some fit figures are still unpublished, so this verdict is not confirmed.

Sources checked · How we source numbers
Movements to scale: TMI NH35, Seiko 4R35Dial side and side section at one scale, hand holes enlarged 8:1. A TMI NH35: Ø 27.4, H 5.32, date 3H, crown 3H. B Seiko 4R35: Ø 27.4, H 5.32, date 3H, crown — (vs A: Ø 0 H 0 mm).A Ø 27.4B Ø 27.4A 5.32B 5.32SIDE · HEIGHTS ON ONE BASELINEHAND HOLES · 8:1A hour 1.5 · minute 0.88 · second 0.198B hand holes —A TMI NH35Ø 27.4 · H 5.32 · date 3H · crown 3HB Seiko 4R35Ø 27.4 · H 5.32 · date 3H · crown —vs A: Ø 0 H 0 mm
NH35 vs 4R35 to one scaleDrawing from data, not a photo · mm

Published figures

Differences are highlighted. Each number links to its source; an empty field says what is missing.

NH35 vs 4R35 specification comparison
FigureATMI NH35BSeiko 4R35
Diameter27.4 mm127.4 mm2secondary source
Casing diameterone side only29.36 mm1not in the documents we read
Size in lignesone side only12‴3not published
Height5.32 mm15.32 mm2secondary source
Jewelsdiffers243235
2 sources disagree; show every value
  • manufacturer 235
  • secondary source 23, 242
Beat rate21,600 bph321,600 bph5
Power reserve41 h441 h5
2 sources disagree; show every value
  • manufacturer 41 h5
  • secondary source 40, 41 h2
Accuracy (maker)differs−20 to +40 s/day4−35 to +45 s/day6
Lift angleone side only53°4not in the documents we read
Hands and functionshours, minutes, centre seconds, date3hours, minutes, centre seconds, date5
Hacking secondsYes3Yes5
Hand windingYes4Yes5
Date window3H4 · 3H, 6H, 9H83H2secondary source
Do not set the datediffers21:00–04:00921:00–01:005
Crownone side only3H4 · 4H10not in the documents we read
Hand holesone side onlyhour 1.5 · minute 0.88 · second 0.198 mm8not published by Seiko
Dial feetone side only1:36, 7:338 · 1:36, 7:338not in the documents we read
Dial centre holeone side only2.05 mm8not published

Can 4R35 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.

Drop-in· not confirmed
  • =diameterSame movement diameter: 27.4 mm.
  • =heightSame height: 5.32 mm.
  • =dateDate window at 3H on both.

Not published, so not checked: hand holes for 4R35; crown position for 4R35; dial feet for 4R35.

Check the actual case, stem height and parts before ordering. Compare another pair.

Sources

Documents checked · Report a wrong number

  1. 1Time Module Ltd. — Watch Movement Specification and Drawing - Standard Mechanical Movement NH35A · pdf · read
  2. 2Grail Watch — Grail Watch Reference: Seiko Cal. 4R35 · html · read
  3. 3Time Module Ltd. — Product Line-Up - Mechanical (NH0&NH3); NH34/NH35/NH36 product blocks · html · read
  4. 4Time Module Ltd. — Technical Guide & Parts Catalogue, Cal.NH3 Series (NH34A/35A/36A/37A/38A/39A) - Automatic Mechanical · pdf · read
  5. 5Seiko Watch Corporation — Instructions: Seiko Automatic Diver's Watch Cal. 4R15/4R16/4R35/4R36/7S26/7S35/7S36 (English) · pdf · read
  6. 6Seiko Watch Corporation — Instructions: Diver's Watch for Air Diving, Cal. 4R35 / 4R36 (English) · pdf · read
  7. 7Seiko Watch Corporation — Instructions: Mechanical watch, Cal. 4R35 / 4R36 / 4R37 / 4R38 / 4R71 / 4R72 / 4R39 (English) · pdf · read
  8. 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
  9. 9Time Module Ltd. — Operation Manual, Cal.NH3 Series (NH34A/35A/36A/37A/38A/39A) · pdf · read
  10. 10Lucius Atelier (seller) — Seiko Mod Dial Compatibility Guide: NH34, NH35, NH36 (blog article) · html · read