Prospex Speedtimer Mechanical
Ref. SPB513
- Case diameter
- 39.5 mm
- Manufacturer spec
- Lug-to-lug
- 44.5 mm
- Manufacturer spec
- Thickness
- 12 mm
- Manufacturer spec
- Lug width
- 20 mm
- Manufacturer spec
Retail price $995 (US, Oct 2026)
How the Prospex Speedtimer Mechanical wears
Its lugs add only 5 mm to the 39.5 mm case, against 7.1 mm typical across the almanac, so it wears smaller than its diameter suggests.
On our fit model it sits best on wrists from 6.25" to 7.5" (15.9–19.1 cm); below 6.25" the lugs start to reach the edge of the wrist.
At 12 mm thick it is thicker than 52% of the 52 other sport watches we've measured, so expect it to sit tall on the wrist.
Its 20 mm lug width is one of the most common strap sizes; 104 other watches here share it, so aftermarket straps are easy to find.
Will the Prospex Speedtimer Mechanical fit your wrist?
With a 44.5 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.
| Wrist | Flat width (est.) | Fit |
|---|---|---|
| 6" | 47.2 mm | Snug, lugs near the edge |
| 6.5" | 51.2 mm | Ideal fit |
| 7" | 55.1 mm | Ideal fit |
| 7.5" | 59.1 mm | Ideal fit |
| 8" | 63 mm | Wears small |
Specifications
- Reference
- SPB513
- Collection
- Prospex
- Status
- In production
- Case material
- stainless steel (super-hard coating)
- Crystal
- curved sapphire
- Water resistance
- 200 m
- Bezel
- steel bezel with 60-minute scale
- Dial
- cream
- Strap / bracelet
- stainless steel bracelet, three-fold clasp
- Weight
- 154 g
- Style
- Sport, Everyday
Movement
- Caliber
- Seiko 6R55
- Type
- automatic
- Power reserve
- 72 hours
- Jewels
- 24
- Accuracy
- +25/-15 s/day
3 other watches use the Seiko 6R55
Takes 20 mm straps. See other 20 mm watches and straps.
More Prospex references
- SeikoProspex 1965 Diver's Modern Re-interpretationSPB143 · “62MAS reinterpretation”
- Case
- 40.5 mm
- Lug-to-lug
- 47.6 mm
- Thick
- 13.2 mm
- SeikoProspex 1970 Diver's Modern Re-interpretationSPB317 · “Captain Willard”
- Case
- 41 mm
- Lug-to-lug
- 46.9 mm
- Thick
- 12.3 mm
- SeikoProspex AlpinistSPB507
- Case
- 39.5 mm
- Lug-to-lug
- 46.4 mm
- Thick
- 12.7 mm
- SeikoProspex AlpinistSPB503
- Case
- 39.5 mm
- Lug-to-lug
- 46.4 mm
- Thick
- 12.7 mm
- SeikoProspex AlpinistSPB121 · “Alpinist”
- Case
- 39.5 mm
- Lug-to-lug
- 46.4 mm
- Thick
- 13.2 mm
- SeikoProspex AlpinistSPB209
- Case
- 39.5 mm
- Lug-to-lug
- 46.4 mm
- Thick
- 13.2 mm
- SeikoProspex AlpinistSPB505
- Case
- 39.5 mm
- Lug-to-lug
- 46.4 mm
- Thick
- 12.7 mm
- SeikoProspex Diver SamuraiSRPB49 · “Samurai”
- Case
- 43.8 mm
- Lug-to-lug
- 48 mm
- Thick
- 13 mm
- SeikoProspex Diver's 200mSPB103 · “Sumo”
- Case
- 45 mm
- Lug-to-lug
- 52.6 mm
- Thick
- 12.9 mm
- SeikoProspex Diver's 200mSPB101 · “Sumo”
- Case
- 45 mm
- Lug-to-lug
- 52.6 mm
- Thick
- 12.9 mm
- SeikoProspex Land Mechanical 38mmSPB249
- Case
- 38 mm
- Lug-to-lug
- 46.2 mm
- Thick
- 12.9 mm
- SeikoProspex Sea TurtleSRPE93 · “Turtle”
- Case
- 45 mm
- Lug-to-lug
- 47.7 mm
- Thick
- 13.4 mm
- SeikoProspex Speedtimer Solar ChronographSSC911
- Case
- 41.4 mm
- Lug-to-lug
- 45.9 mm
- Thick
- 13 mm
- SeikoProspex Speedtimer Solar Chronograph 39mmSSC961
- Case
- 39 mm
- Lug-to-lug
- 45.5 mm
- Thick
- 13.3 mm
Watches that wear the same size
Other watches within 1.5 mm of its lug-to-lug.
- Christopher WardThe Twelve 40mmC12-40ADA1-S00B3-B0
- Case
- 40 mm
- Lug-to-lug
- 44.5 mm
- Thick
- 9.9 mm
- DoxaSUB 300T Professional840.10.351.10
- Case
- 42.5 mm
- Lug-to-lug
- 44.5 mm
- Thick
- 13.7 mm
- Grand SeikoHeritage 9F Quartz 37mmSBGX261
- Case
- 37 mm
- Lug-to-lug
- 44.6 mm
- Thick
- 10 mm
- Seiko5 Sports Field Sports Style 36mmSRPJ85
- Case
- 36.4 mm
- Lug-to-lug
- 44.4 mm
- Thick
- 12.5 mm
- Grand SeikoGrand Seiko Elegance Manual-WindSBGW231
- Case
- 37.3 mm
- Lug-to-lug
- 44.3 mm
- Thick
- 11.6 mm
- HamiltonKhaki Field Murph 38mmH70405730 · “Murph”
- Case
- 38 mm
- Lug-to-lug
- 44.7 mm
- Thick
- 11.1 mm
Same 20 mm lug width
All 20 mm watchesThese take the same straps as the Prospex Speedtimer Mechanical.
- BalticAquascaphe Classic
- Case
- 39 mm
- Lug-to-lug
- 47 mm
- Thick
- 13 mm
- BalticAquascaphe GMT MK II
- Case
- 39.5 mm
- Lug-to-lug
- 47 mm
- Thick
- 13.8 mm
- BalticAquascaphe MK2 37mm
- Case
- 37 mm
- Lug-to-lug
- 45 mm
- Thick
- 12.9 mm
- BalticAquascaphe MK2 39.5mm
- Case
- 39.5 mm
- Lug-to-lug
- 47 mm
- Thick
- 12.9 mm
- BalticBicompax 002
- Case
- 38 mm
- Lug-to-lug
- 47 mm
- Thick
- 13 mm
- BalticHMS 002
- Case
- 38 mm
- Lug-to-lug
- 47 mm
- Thick
- 13 mm