Seiko Cal. 5640 - 920

The Seiko 5640-920 represents an important milestone in Seiko's 1970 lineup. Powered by the 5640 caliber with 32j jewels beating at 36,000 bph, it delivers a 36 hours power reserve. [seikata-wm-465ac4efc2b4]

Also known as: Crown

Specifications

Movement

Automatic

Case Material

Hardlex-Coated Steel

Case Width

37mm

Case Thickness

13.8mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Bidirectional

Water Resistance

30m

Dial Color

Green

Jewels

32j

Frequency

36,000 bph

Power Reserve

36 hours

Year

1970

Related Models

• Seiko 7093-575
• Seiko 7169-684
• Seiko 4583-349
• Seiko 7175-807
• Seiko 7149-188
• Seiko 5266-614
• Seiko 6687-376
• Seiko 7079-184
• Seiko 3889-934
• Seiko 7183-612
• Seiko 6691-528
• Seiko 0742-896