Omega
Omega Speedmaster Automatic "Reduced"
Omega
3510.20
Share:
Details & Specifications
Description
The Omega Speedmaster Mark 40 ref. 3510.20 is one of the most refined and underappreciated references in the Speedmaster family — a 39mm automatic chronograph that takes the iconic Speedmaster silhouette and architecture and reinterprets it through a more dressy, silver-dialled lens that gives the watch an entirely different character from the all-black Professional Moonwatch.
The Mark 40 designation refers to the triple calendar complication that distinguished these references from the standard Speedmaster Reduced, with the date aperture at 3 o'clock adding everyday practicality to the chronograph's timing functions. The white silver-toned dial is beautifully executed — three matching sub-dials at 9, 6 and 3 o'clock in the characteristic tri-compax layout (60-minute counter at 9, small seconds at 6, and 12-hour counter at 3) create an integrated, harmonious dial composition that wears as elegantly as it performs. Applied silver baton hour markers and matching hands complete a dial of considerable refinement.
The stainless steel case carries the Speedmaster's characteristic angular case architecture and engraved tachymeter bezel — the scale machined directly into the steel rather than printed on an aluminium insert — with screw-locked chronograph pushers at 2 and 4 o'clock and the winding crown at 3 o'clock. The Calibre 1151, an automatic movement based on the ETA 2892-A2 with Valjoux 7750 architecture producing the tri-compax sub-dial layout, powers the watch at 28,800 vph — a movement that offers the convenience of automatic winding while delivering a more refined, symmetrical dial layout than the modular Calibre 3220 found in the standard Speedmaster Reduced.
Water resistance is rated to 30 metres. The stainless steel bracelet with deployment clasp completes a watch that represents excellent value within the Speedmaster family for the collector who appreciates its quiet distinction.
Specifications:
| Movement | |
| Type | Automatic Self-Winding Chronograph |
| Calibre | Omega 1151 (ETA 2892-A2 / Valjoux 7750 architecture) |
| Functions | Hours, Minutes, Seconds, Chronograph (60-minute and 12-hour counters), Date |
| Frequency | 28,800 vph (4 Hz) |
| Power Reserve | Approx. 44 hours |
| Case | |
| Case Material | Stainless Steel |
| Case Diameter | 39.0 mm |
| Water Resistance | 30m / 100ft (3 bar) |
| Crown | Push-pull crown at 3 o'clock; screw-locked chronograph pushers at 2 and 4 o'clock |
| Bezel | Fixed stainless steel bezel with engraved tachymeter scale |
| Crystal | Scratch-resistant sapphire crystal |
| Dial Colour | White / silver-toned |
| Dial Indicators | Applied silver baton hour markers; matching baton hands; tri-compax sub-dials at 9, 6 and 3 o'clock; date aperture at 3 o'clock |
| Bracelet | |
| Bracelet Material | Stainless steel with alternating brushed and polished links |
| Clasp | Deployment clasp |
| Additional Details | |
| Reference | 3510.20 / 3510.20.00 |
| Collection | Speedmaster Mark 40 |
| Production Period | ca. 1997–2005 |
| Origin | Swiss Made |






