Seiko Cal. 4S15A Movement Parts Catalogue and Technical Guide

Seiko Cal. 4S15A automatic watch movement parts catalogue and technical guide. Provides detailed specifications for this 26.0 mm diameter movement: 25.6 mm casing diameter, 4.17 mm height, 28,800 vibrations per hour (8 beats per second), three-hand display, and 25 jewels. Exploded diagrams show all numbered components for systematic identification during repair and maintenance. Lubrication instructions cover application of Moebius V and Moebius A oils alongside Seiko Watch Oils S-6, S-4, and S-3 at specific wear points. Comprehensive parts lists detail screws, jewels, tubes, and pins with specifications. Hand installation height discrimination table cross-references movement numerals to correct hand stack positioning. Technical remarks guide disassembly and reassembly procedures with practical notes on critical tolerances. Covers automatic winding mechanism with manual hand-winding option, date calendar module, second-setting device, micro-regulating system, and micro-positioning regulator pin adjustment. Essential reference for service technicians and qualified repair professionals working with this common Seiko movement family.