Seiko 4R36

The Caliber 4R36, also known as the 4R36, is an automatic mechanical movement developed and produced by the Japanese watchmaker Seiko. This self-winding mechanism serves as a foundational component in a variety of Seiko timepieces, providing reliable timekeeping and calendar functions. The 4R36 movement incorporates 24 jewels, which are synthetic rubies strategically placed at points of high friction within the gear train. These jewels serve to minimize wear and tear on metal components, contributing to the movement's longevity and consistent performance over time. The balance wheel of the 4R36 oscillates at a frequency of 21,600 vibrations per hour (vph), which translates to 3 Hz. This frequency dictates the rate at which the second hand advances, resulting in six distinct beats per second. For the wearer, this produces a relatively smooth, sweeping motion of the second hand across the dial, a characteristic often associated with mechanical watches. A notable practical feature of the 4R36 is its power reserve of 41 hours. Once fully wound, either through the motion of the wearer's wrist or manual winding via the crown, the movement can operate for approximately 41 hours without requiring further energy input. This allows the watch to be set aside for more than a day and still be running when picked up again. The movement is equipped with several complications beyond basic time-telling. It displays hours, minutes, and seconds through central hands. Additionally, it features a date complication, typically shown in a window on the dial, indicating the current day of the month. Complementing this is a day complication, which displays the current day of the week. Both the date and day functions provide practical utility for daily planning and organization. The Seiko 4R36 movement is integrated into a diverse range of Seiko watches, underscoring its versatility and robust design. It powers models such as the Seiko 5 Sports Sports Style Stainless Steel / Black / NATO (Ref. SRPD55K3) with a 42.5mm case, and the Seiko 5 Sports Sports Style Hard Coating / Black / Bracelet (Ref. SRPD65K1), also 42.5mm. The movement is also found in the larger Seiko Prospex Diver Turtle Stainless Steel / Blue Lagoon / Bracelet (Ref. SRPB11), measuring 45mm. Other watches utilizing this caliber include the Seiko 5 Sports Sports Style Stainless Steel / Pepsi / Bracelet (Ref. SRPD53K1) at 42.5mm, and the Seiko 5 Sports Street Style Hard Coating / Black - Black / NATO (Ref. SRPD79K1), also 42.5mm. Its inclusion across these varied models highlights its role in providing reliable and functional timekeeping for a broad spectrum of watch enthusiasts.

Specifications

Complications

Also Known As

Watches Using This Caliber(48)

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