Sinn
Sinn 104 St Sa I Strap Size — 20mm Lug Width
The Sinn 104 St Sa I has a 20mm lug width, so it takes a 20mm watch strap.
Lug width20mm
| Lug width | 20 mm |
|---|---|
| Case size | 41 mm |
| Lug-to-lug | — |
| Thickness | 11.5 mm |
| Spring bar Ø (typical) | Not confirmed |
| End type | Straight |
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.
▲ Ordinary 20mm spring-bar lugs, so most 20mm straps fit.
Fit & sizing notes for the 104 St Sa I
- 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).
- Strap thickness: at 11.5mm thick it's mid-thickness, so most straps suit it; padded leather and NATOs both balance well.
Sources & corrections
Lug width checked against: Define Watches: 104 St Sa I; Ocarat: 104 St Sa A I MG (104.0131). Last checked 26 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.
Sinn 104 St Sa I — strap questions
What size strap does the 104 St Sa I take?
The Sinn 104 St Sa I has a 20mm lug width, so you need a 20mm watch strap.
Will any 20mm strap fit the 104 St Sa I?
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 104 St Sa I use?
20mm long. We haven't confirmed the diameter for the 104 St Sa I, so measure the original bar with calipers before buying replacements.
Is the 104 St Sa I 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.