Rolex
Rolex Explorer 40 Strap Size — 21mm Lug Width
The Rolex Explorer 40 has a 21mm lug width, so it takes a 21mm watch strap.
Lug width21mm
| Lug width | 21 mm |
|---|---|
| Case size | 40 mm |
| Lug-to-lug | — |
| Thickness | 11.6 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 |
|---|---|---|
| 224270 (Explorer 40) | 40mm, 2023 on | 21mm |
| 124270 (Explorer 36) | 36mm | 19mm |
Strap styles that fit
- NATO / Zulu21mm fits if the strap's thickness clears the case under the bars.
- PerlonWoven pass-through, 21mm.
- 2-piece leatherStraight ends fit flush.
- Rubber / siliconeDivers & sports fit well.
- Milanese / meshStraight-end 21mm mesh fits.
- Metal braceletNeeds 21mm end-links shaped for this case.
▲ 21mm: wider than the 19mm Explorer 36, so the two don't share straps.
Fit & sizing notes for the Explorer 40
- Width: buy 21mm straps. Tapered straps listed as 21/19mm or 21/17mm fit too; only the first number has to match. See strap sizes explained.
- Spring bars: 21mm long. We haven't confirmed the diameter for this model, so measure the old bar before buying replacements (spring bar sizes).
- Odd size: 21mm straps are harder to find; a 20mm strap fits with a small gap, but never go wider. Odd lug width options.
- Strap thickness: at 11.6mm thick it's mid-thickness, so most straps suit it; padded leather and NATOs both balance well.
Sources & corrections
Lug width checked against: Monochrome: Explorer 40 ref. 224270; Time+Tide: Explorer 40; Bob's Watches: Explorer 224270; Delugs: Explorer 40 224270-0001. Last checked 26 October 2026.
Spec wrong for your watch? Send us a correction with your reference number.
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Rolex Explorer 40 — strap questions
What size strap does the Explorer 40 take?
The Rolex Explorer 40 has a 21mm lug width, so you need a 21mm watch strap.
Will any 21mm strap fit the Explorer 40?
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 21mm end-links made for this model.
What spring bar size does the Explorer 40 use?
21mm long. We haven't confirmed the diameter for the Explorer 40, so measure the original bar with calipers before buying replacements.
Is the Explorer 40 good for strap swapping?
Yes. With standard 21mm spring-bar lugs, NATO, leather, rubber and mesh straps can all be fitted with a spring-bar tool.