Seiko Cal. 5631 - 330

The 5631-330 is a sought-after Hand-Winding piece from Seiko's golden era. Powered by the 5631 caliber with 18j jewels beating at 28,800 bph, it delivers a 68 hours power reserve. [seikata-wm-2c35b833e5b4]

Also known as: Sportsmatic, Bellmatic

Specifications

Movement

Hand-Winding

Case Material

PVD Black

Case Width

39mm

Case Thickness

11.8mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

90m

Dial Color

Navy

Jewels

18j

Frequency

28,800 bph

Power Reserve

68 hours

Year

1965

Related Models

• Seiko 4457-432
• Seiko 3875-845
• Seiko 7030-356
• Seiko 7193-355
• Seiko 6248-444
• Seiko 7117-410
• Seiko 4544-526
• Seiko 6157-850
• Seiko 6139-338
• Seiko 3821-349
• Seiko 7110-444
• Seiko 6628-928