Seiko Cal. 5618 - 631

The Seiko 5618-631 represents an important milestone in Seiko's 1972 lineup. Powered by the 5618 caliber with 18j jewels beating at 28,800 bph, it delivers a 40 hours power reserve. [seikata-wm-4477b509948f]

Also known as: Sumo, Sportsmatic

Specifications

Movement

Kinetic

Case Material

Gold-Plated

Case Width

34mm

Case Thickness

9.6mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

70m

Dial Color

Green

Jewels

18j

Frequency

28,800 bph

Power Reserve

40 hours

Year

1972

Related Models

• Seiko 6145-393
• Seiko 0786-512
• Seiko 7142-641
• Seiko 5298-647
• Seiko 6278-299
• Seiko 6619-190
• Seiko 6380-765
• Seiko 6333-710
• Seiko 4523-126
• Seiko 4440-305
• Seiko 6331-668
• Seiko 6284-754