Seiko
Seiko SKX013 Strap Size — 20mm Lug Width
The Seiko SKX013 has a 20mm lug width, so it takes a 20mm watch strap.
Lug width20mm
| Lug width | 20 mm |
|---|---|
| Case size | 38 mm |
| Lug-to-lug | 44 mm |
| Thickness | 13 mm |
| Spring bar Ø (typical) | Not confirmed |
| End type | Straight |
Which reference do you have?
Similar-looking models can take different straps. Your reference number is on the case back or your papers.
| Model | Case | Strap |
|---|---|---|
| SKX013 | 38mm | 20mm |
| SKX007 / SKX009 | 42.5mm | 22mm |
Strap styles that fit
- NATO / Zulu20mm fits if the strap's thickness clears the case under the bars.
- PerlonWoven pass-through, 20mm.
- 2-piece leatherStraight ends fit flush.
- Rubber / siliconeDivers & sports fit well.
- Milanese / meshStraight-end 20mm mesh fits.
- Metal braceletNeeds 20mm end-links shaped for this case.
▲ The midsize SKX: 20mm, not 22mm like the SKX007.
Fit & sizing notes for the SKX013
- Width: buy 20mm straps. Tapered straps listed as 20/18mm or 20/16mm fit too; only the first number has to match. See strap sizes explained.
- Spring bars: 20mm long. We haven't confirmed the diameter for this model, so measure the old bar before buying replacements (spring bar sizes).
- Wrist fit: at 44mm lug-to-lug it should sit within the top of wrists from about 14.7cm up (rule of thumb: lug-to-lug under ~30% of wrist size). That's longer than 8% of the watches in our index. See what size watch suits your wrist.
- Strap thickness: at 13mm thick it's a chunky case: thicker padded leather, rubber/FKM or a heavier NATO balance it visually; very thin straps can look undersized.
The SKX013 is the 38mm midsize version of Seiko's classic diver. It looks almost identical to the SKX007 in photos, so strap listings often mix them up: the SKX013 needs 20mm straps, the SKX007 22mm. Lug-to-lug is only about 44mm, which is why it suits smaller wrists.
Sources & corrections
Lug width checked against: Bespoke Unit: SKX013. Last checked 24 October 2026.
Spec wrong for your watch? Send us a correction with your reference number.
Get the right strap
Links open Amazon — we may earn a commission at no cost to you.
Seiko SKX013 — strap questions
What size strap does the SKX013 take?
The Seiko SKX013 has a 20mm lug width, so you need a 20mm watch strap.
Will any 20mm strap fit the SKX013?
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 20mm end-links made for this model.
What spring bar size does the SKX013 use?
20mm long. We haven't confirmed the diameter for the SKX013, so measure the original bar with calipers before buying replacements.
Is the SKX013 good for strap swapping?
Yes. With standard 20mm spring-bar lugs, NATO, leather, rubber and mesh straps can all be fitted with a spring-bar tool.