Seiko Cal. 5631 - 301

This Automatic model from 1974 features a 37mm PVD Black case. It features a Blue Sunburst dial protected by a Hardlex crystal and offers 90m of water resistance. [seikata-wm-7a9b62dac850]

Also known as: Sumo, Crown

Specifications

Movement

Automatic

Case Material

PVD Black

Case Width

37mm

Case Thickness

9.8mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

90m

Dial Color

Blue Sunburst

Jewels

33j

Frequency

21,600 bph

Power Reserve

69 hours

Year

1974

Related Models

• Seiko 4589-262
• Seiko 6656-793
• Seiko 3824-659
• Seiko 4456-343
• Seiko 4430-153
• Seiko 5231-840
• Seiko 6236-270
• Seiko 6649-915
• Seiko 4594-878
• Seiko 4587-969
• Seiko 3825-348
• Seiko 6158-456