Seiko - Precision Second Setting Pocket Watch With Engraved Case Back No. 9435 - 6310-0010 - 1970-1979

Introduction

This is a Seiko Precision 21-jewel open-face pocket watch, reference 6310-0010, bearing the caseback inscription 東北鉄 9435 — stamped by the Tohoku Railway Administration Bureau of Japanese National Railways. The movement is the manual-winding caliber 6310A.

Historical / Era context

This watch belongs to Seiko's long-running 'Type 19' lineage of open-face railway pocket watches, produced for issue to Japanese National Railways (JNR / 国鉄) operating staff. Bureau-stamped examples like this one — marked with the abbreviated bureau name ending in 鉄 — were individually numbered and issued as official working instruments, not sold commercially. The 東北鉄 mark identifies the Tohoku Railway Administration Bureau, one of the regional operating bureaux of JNR, and the supply number 9435 is the bureau's own inventory number for this piece. The 'SECOND SETTING' feature allowed the running seconds hand to be halted and reset precisely to a time signal, a requirement for safe railway operation.

Condition

The watch is running, with a measured rate of approximately +2 minutes per day (gaining). The watch was checked lying flat (dial up) after a full wind. This is a spot check at the time of listing; as a vintage mechanical watch the rate in actual wear varies with position and winding state, and long-term accuracy is not guaranteed. As a vintage timepiece it may benefit from a service.

Case: The chrome-plated case is in good condition overall. The caseback exterior shows light surface scratching consistent with normal handling. The mid-band and bezel rim carry scattered fine scratches. The caseback is stamped 東北鉄 / 9435 on the exterior in clean, legible characters. The case material code ACRP is stamped inside the caseback lid, indicating a white base-metal plating mark.

Dial: The white dial is clean and legible with no staining, damage, or significant soiling visible. The printed Arabic numerals and all text — including 'SEIKO PRECISION 21 JEWELS' and 'SECOND SETTING' — are crisp and well-defined.

Crystal: The mineral crystal is intact, clear, and free of cracks. Fine light surface marks are present but do not impair legibility.

Movement: The watch is running. The caliber 6310A manual-winding movement, visible with the caseback opened, is signed 'SEIKO 21 JEWELS 6310A JAPAN' on the mainplate. The finish and architecture are clean, with no rust or damage visible.

Accessories: No chain, box, or papers are included. The watch is offered as shown.

Please review all photographs carefully for the detailed condition.

Specifications

Brand: Seiko
Model: SEIKO PRECISION
Reference: 6310-0010
Movement: Manual winding mechanical movement
Jewels: 21 jewels
Case material: Chromed
Case diameter: approx. 48.3 mm
Total length including crown: approx. 61 mm
Total length including crown and ring: approx. 71.5 mm
Dial color: White
Period: 1970-1979
Weight: approx. 81 g
Accessories: None (watch only)
In working order: Yes
Timekeeping: approx. +2 minutes per day (checked lying flat after a full wind)

Closing note

A genuine bureau-issued Seiko Precision railway pocket watch with clear Tohoku Railway Administration Bureau stamping and inventory number — a historically meaningful piece for collectors of Japanese horology and JNR artefacts. Please examine all photographs carefully, as they form part of the description.
As with all vintage timepieces, please examine the provided photographs carefully to satisfy yourself with the condition before bidding. The watch is sold as a vintage collectible; water resistance and future maintenance are not guaranteed.
The item is carefully packed and shipped from Japan with tracking.
Import duties, taxes and customs charges are the buyer's responsibility.