Seiko
Seiko Alpinist Strap Size — 20mm Lug Width
The Seiko Alpinist has a 20mm lug width, so it takes a 20mm watch strap.
Lug width20mm
| Lug width | 20 mm |
|---|---|
| Case diameter | 39 mm |
| Lug-to-lug | 46 mm |
| Thickness | 12 mm |
| Spring bar Ø | 1.8 mm |
| End type | Straight |
Strap styles that fit
- NATO / ZuluSingle-pass — always fits 20mm.
- PerlonWoven pass-through, 20mm.
- 2-piece leatherStraight ends fit flush.
- Rubber / siliconeDivers & sports fit well.
- Milanese / meshSlides to 20mm.
- Metal braceletNeeds 20mm model-specific end-links.
▲ Classic dress-diver.
Get the right strap
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Seiko Alpinist — strap questions
What size strap does the Alpinist take?
The Seiko Alpinist has a 20mm lug width, so you need a 20mm watch strap.
Will any 20mm strap fit the Alpinist?
Yes for straight-lug styles (NATO, leather, rubber). A metal bracelet needs 20mm end-links made for this model.
What spring bar size does the Alpinist use?
Roughly 1.8mm diameter.
Is the Alpinist good for strap swapping?
Very — with standard 20mm lugs you can switch between NATO, leather, rubber and mesh straps in seconds with a spring-bar tool.