Omega Railmaster
Most Omega Railmaster references take a 20 mm watch strap: 15 of 38. The lug width follows the case size: 38 mm case → 19 mm, 39 mm case → 20 mm, 40 mm case → 20 mm and 42 mm case → 21 mm.
Omega Railmaster lug width by case size
38 references measured. Updated 2026-10-29.
| Case | Lug width | References | Watch strap attachment | For example |
|---|---|---|---|---|
| 36 mm | 19 mm | 2 | — | 2504.52.00, 2804.52.37 |
| 38 mm | 19 mm | 6 | — | 220.10.38.20.01.002, 220.10.38.20.01.003, 235.10.38.20.06.001 |
| 39 mm | 20 mm | 9 | — | 2103.52.00, 2108.52.00, 2503.52.00 |
| 40 mm | 20 mm | 6 | — | 220.10.40.20.01.001, 220.10.40.20.03.001, 220.10.40.20.06.001 |
| 41 mm | 21 mm | 1 | — | 2502.52.00 |
| 42 mm | 21 mm | 9 | — | 2512.52.00, 2512.53.00, 2512.54.00 |
| 49 mm | 24 mm · 18 mm on 2 | 5 | — | 221.53.49.10.01.001, 221.53.49.10.01.002, 2806.52.37 |
References that take a different watch strap
- 2806.72.31: 18 mm, not the 24 mm of most 49 mm cases
- 2806.77.40: 18 mm, not the 24 mm of most 49 mm cases
Questions about the Omega Railmaster
Do all Omega Railmaster case sizes take the same watch strap?
No. The lug width changes with the case size: the 38 mm case takes 19 mm, the 39 mm case takes 20 mm, the 40 mm case takes 20 mm, the 42 mm case takes 21 mm and the 49 mm case takes 24 mm. Check your case diameter before you buy.
Every Omega Railmaster reference
- Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster Yellow Gold / Bracelet2103.52.00
20 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster Yellow Gold / Bracelet / China Train2108.52.00
20 mm - Railmaster Omega Co-Axial Master Chronometer 38 / 60th Anniversary220.10.38.20.01.002
19 mm - Railmaster Omega Co-Axial Master Chronometer 38 / 60th Anniversary / Trilogy Set220.10.38.20.01.003
19 mm - Railmaster Omega Co-Axial Master Chronometer 40 Stainless Steel / Grey / Bracelet220.10.40.20.01.001
20 mm - Railmaster Omega Co-Axial Master Chronometer 40 Stainless Steel / Blue / Bracelet220.10.40.20.03.001
20 mm - Railmaster Omega Co-Axial Master Chronometer 40 Stainless Steel / Silver / Bracelet220.10.40.20.06.001
20 mm - Railmaster Omega Co-Axial Master Chronometer 40 Stainless Steel / Grey / Strap220.12.40.20.01.001
20 mm - Railmaster Omega Co-Axial Master Chronometer 40 Stainless Steel / Blue / NATO220.12.40.20.03.001
20 mm - Railmaster Omega Co-Axial Master Chronometer 40 Stainless Steel / Silver / Strap220.12.40.20.06.001
20 mm - Seamaster Aqua Terra 150M Hand Wound 49.2 Railmaster Red Gold / Brown Alligator221.53.49.10.01.001
24 mm - Seamaster Aqua Terra 150M Hand Wound 49.2 Railmaster White Gold / Brown Alligator221.53.49.10.01.002
24 mm - Railmaster Omega Co-Axial Master Chronometer 38 Stainless Steel / Grey Gradient / Bracelet235.10.38.20.06.001
19 mm - Railmaster Omega Co-Axial Master Chronometer Small Seconds 38 Stainless Steel / Beige Gradient / Bracelet235.10.38.20.13.001
19 mm - Railmaster Omega Co-Axial Master Chronometer 38 Stainless Steel / Grey Gradient235.12.38.20.06.001
19 mm - Railmaster Omega Co-Axial Master Chronometer Small Seconds 38 Stainless Steel / Beige Gradient235.12.38.20.13.001
19 mm - Seamaster Aqua Terra 150M Co-Axial 42.2 Railmaster / Bracelet2502.52.00
21 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster / Bracelet2503.52.00
20 mm - Seamaster Aqua Terra 150M Co-Axial 36.2 Railmaster / Bracelet2504.52.00
19 mm - Seamaster Aqua Terra 150M Automatic 42.2 Railmaster Chronograph / Bracelet2512.52.00
21 mm - Seamaster Aqua Terra 150M Automatic 42.2 Railmaster Chronograph / Bracelet / China Explorer Red2512.53.00
21 mm - Seamaster Aqua Terra 150M Co-Axial 42.2 Railmaster Chronograph / Bracelet / China Explorer Yellow2512.54.00
21 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster Yellow Gold / Black Alligator2603.52.31
20 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster Yellow Gold / Brown Alligator2603.52.37
20 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster Yellow Gold / Brown Alligator / China Train2608.52.31
20 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster Yellow Gold / Brown Alligator / China2608.52.37
20 mm - Seamaster Aqua Terra 150M Co-Axial 42.2 Railmaster / Black Alligator2802.52.31
21 mm - Seamaster Aqua Terra 150M Co-Axial 42.2 Railmaster / Brown Alligator2802.52.37
21 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster / Black Alligator2803.52.31
20 mm - Seamaster Aqua Terra 150M Co-Axial 39.2 Railmaster / Brown Alligator2803.52.37
20 mm - Seamaster Aqua Terra 150M Co-Axial 36.2 Railmaster / Brown Alligator2804.52.37
19 mm - Seamaster Aqua Terra 150M Hand Wound 49.2 Railmaster Stainless Steel / Brown Alligator2806.52.37
24 mm - Seamaster Aqua Terra 150M Hand Wound 49.2 Railmaster Stainless Steel / Blue MOP2806.72.31
18 mm - Seamaster Aqua Terra 150M Hand Wound 49.2 Railmaster Stainless Steel / Red MOP2806.77.40
18 mm - Seamaster Aqua Terra 150M Automatic 42.2 Railmaster Chronograph / Black Alligator2812.52.31
21 mm - Seamaster Aqua Terra 150M Automatic 42.2 Railmaster Chronograph / Brown Alligator2812.52.37
21 mm - Seamaster Aqua Terra 150M Co-Axial 42.2 Railmaster Chronograph / China Explorer Red2812.53.81
21 mm - Seamaster Aqua Terra 150M Co-Axial 42.2 Railmaster Chronograph / China Explorer Yellow2812.54.82
21 mm
Other Omega families
Inside each one the lug width often changes: it is the reference that decides.
- Constellation 945
- De Ville 754
- Aqua Terra 584
- Seamaster Diver 300M 272
- Seamaster Planet Ocean 242
- Speedmaster (Non-Moonwatch) 196
- Speedmaster Moonwatch 163
- LadyMatic 103
- Trésor 99
- Museum Collection 64
- Speedmaster Broad Arrow 45
- Speedmaster Reduced 45
All Omega families → · Why the size changes inside a family →