Seiko
Seiko 5 (SNK) Strap Size — 18mm Lug Width
The Seiko 5 (SNK) has a 18mm lug width, so it takes a 18mm watch strap.
Lug width18mm
| Lug width | 18 mm |
|---|---|
| Case size | 37 mm |
| Lug-to-lug | 43.5 mm |
| Thickness | 11 mm |
| Spring bar Ø (typical) | 1.8 mm |
| End type | Straight |
Strap styles that fit
- NATO / Zulu18mm fits if the strap's thickness clears the case under the bars.
- PerlonWoven pass-through, 18mm.
- 2-piece leatherStraight ends fit flush.
- Rubber / siliconeDivers & sports fit well.
- Milanese / meshStraight-end 18mm mesh fits.
- Metal braceletNeeds 18mm end-links shaped for this case.
Fit & sizing notes for the Seiko 5 (SNK)
- Width: buy 18mm straps. Tapered straps listed as 18/16mm or 18/14mm fit too; only the first number has to match. See strap sizes explained.
- Spring bars: 18mm long, about 1.8mm diameter (spring bar sizes).
- Wrist fit: at 43.5mm lug-to-lug it should sit within the top of wrists from about 14.5cm up (rule of thumb: lug-to-lug under ~30% of wrist size). That's longer than 6% of the watches in our index. See what size watch suits your wrist.
- Strap thickness: at 11mm thick it's mid-thickness, so most straps suit it; padded leather and NATOs both balance well.
Sources & corrections
Lug width from widely published specifications. Case sizes and references vary, so measure your own watch if anything looks different.
Spec wrong for your watch? Send us a correction with your reference number.
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Seiko 5 (SNK) — strap questions
What size strap does the Seiko 5 (SNK) take?
The Seiko 5 (SNK) has a 18mm lug width, so you need a 18mm watch strap.
Will any 18mm strap fit the Seiko 5 (SNK)?
Most will. Width is the main thing to match, but also check that the strap's spring-bar holes suit the bars, and that the strap is thin enough to clear the case between the lugs. A metal bracelet needs 18mm end-links made for this model.
What spring bar size does the Seiko 5 (SNK) use?
18mm long and about 1.8mm in diameter (a typical figure; measure the original bar to be sure).
Is the Seiko 5 (SNK) good for strap swapping?
Yes. With standard 18mm spring-bar lugs, NATO, leather, rubber and mesh straps can all be fitted with a spring-bar tool.