Seiko 4R15

4R15 and 4R16 are two related automatic upper-midrange watch movements from Seiko.

Overview

The 4R15 family was introduced in 2008 as mainstream automatic watch movements for Seiko watches. It is based on the hacking/hand-winding Seiko 6R15 but lacks these advanced features. Both of these movement families are based on the basic Seiko 7S26 movement, and all share some components. Unlike the 7S26 family (and the hacking/hand-winding brother, 4R35/6/7/8/9), the 4R15/16 have a long 50 hour power reserve thanks to an advanced Spron 510 mainspring. This is shared with the 6R15 as well.

Variants

Like most Seiko movements, the 4R15/16 family operate at 21,600 A/h. All models feature sweep hour, minute, and second hands. The 4R15 features a date window, while the 4R16 has both day and date in a window. Both have 22 jewels.

Movement	Beat	Hands	Date	Subdial	Jewels	Power reserve
4R15	21,600 A/h	Hour, minute, seconds	Date	None	22	50 hours
4R16			Day and date

Applications

The 4R15 and 4R16 are used in many Seiko "Superior" watches, most in the "SRP" model series. These featured upmarket features from the common Seiko 5 line, such as sapphire crystals and metal bracelets with solid end links.

External links

• Seiko 4R36 -The Family In Brief
• Seiko 4R Family Reference

Description: Automatic movement Functions: Hours, minutes, seconds Central seconds Rapid calendar advance Data: 22 jewels 21,600 A/h Power reserve 41 hours Spron 510 mainspring Production period: 2008-Present