Seiko against TUDOR
Seiko SSK001 vs TUDOR M79470-0001
11 published specifications differ between these two. Every figure below is what the manufacturer states for that reference; nothing is inferred from the other watch.
What differs
| Specification | ||
|---|---|---|
| Case | Stainless steel, 42.5 mm | 39mm steel case with polished and satin finish |
| Diameter | 42.5 mm | 39 mm |
| Water resistance | 10 bar | Waterproof to 200m (660 ft) |
| Crystal | Hardlex with magnified glass | Domed sapphire crystal |
| Bezel | Rotating bezel with 24-hour display | 24-hour graduated fixed bezel in satin-brushed steel |
| Bracelet | 22 mm between the lugs | Riveted steel bracelet with polished and satin finish |
| Clasp | Three-fold clasp with push button release, with secure lock | TUDOR T-fit clasp with rapid adjustment |
| Calibre | 4R34 | Manufacture Calibre MT5652 |
| Movement | Automatic with manual winding | Self-winding mechanical movement with bidirectional rotor system, built-in architecture |
| Power reserve | Approximately 41 hours | Approximately 70 hours |
| Movement notes | 24-hour hand for dual time display, stop second hand function and date display. Magnetic resistance 4,800 A/m. LumiBrite on hands and indexes. Total weight 161.0 g. No daily precision figure is published for this reference. | TUDOR states a five-year transferable guarantee with no registration or periodic maintenance checks required. |
Stated for one, not the other
These rows cannot be compared, because one maker publishes the figure and the other does not. An empty cell is a gap in the manufacturer's documentation, not a gap in the watch — and not a licence to fill it in from the other column.
| Thickness | 13.6 mm | not stated |
|---|---|---|
| Lug to lug | 46 mm | not stated |
| Lug width | 22 mm | not stated |
| Dial | not stated | Black, domed |
| Case back | See-through and screw case back | not stated |
| Crown | not stated | Screw-down winding crown in steel with the TUDOR rose in relief |
| Jewels | 24 | not stated |
| Certification | not stated | COSC |
What the differences cost you
Each note below follows from the published figures in the tables above — what they mean for intake, for a listing, and for the handover. Nothing here estimates a price or a margin.
You will have to measure one of these
Lug to lug is published for the SSK001 but not for the M79470-0001. It is the figure that actually predicts fit, so measure the M79470-0001 yourself with callipers and say in the listing that the number is your own measurement, not the maker's.
These reach different buyers
42.5 mm on the SSK001 against 39 mm on the M79470-0001. Diameter is a poor predictor of how a watch actually sits, but it is the field buyers filter on, so the two land in front of different people. Do not let one listing's photographs or copy stand in for the other.
Do not describe these the same way
200 metres on the M79470-0001 against 100 on the SSK001. Both are more than daily life asks for, so the number is a listing-accuracy question rather than a practical one: quote each watch its own figure, and remember that neither rating survives an unserviced case by itself.
One survives the weekend and one does not
70 hours on the M79470-0001 against 41 on the SSK001. Below about sixty hours a watch left off the wrist from Friday is stopped by Monday. Wind both fully at intake and confirm they reach the stated figure — a short reserve leaves a tired barrel nowhere to hide, and it is the kind of fault a buyer reports in week two.
What to check on each
SSK001
- Grade the crystal as Hardlex, not as sapphire. Hardlex scratches where sapphire would not, and those scratches can often be polished out, so a marked crystal here is a cheap fix rather than a replacement.
- Check the magnifier over the date for lifting at its edges. It is a separate element bonded to the crystal and it can detach, which is a fault a photograph rarely shows.
- Note that Seiko publishes no daily accuracy figure for this reference. Do not borrow the +25 to −15 quoted for the 6R calibres, and say in the listing that the maker does not state one.
M79470-0001
- Do not try to turn the bezel. TUDOR specifies it as fixed, so an immovable bezel is correct and forcing it is how a good example gets damaged.
- Confirm the 24-hour bezel is satin-brushed steel with no rotating insert, which distinguishes this reference from the GMT models in the same family.
- Run the T-fit rapid adjustment through its positions and confirm each one locks under a firm pull.
Sources
- Seiko official product page for reference SSK001 (Seiko 5 Sports, SKX series) - Caliber Number: 4R34; Movement Type: Automatic with manual winding; Power reserve: Approx. 41 hours; Jewels: 24; Case Material: Stainless steel; Case Size: Thickness:13.6mm; Diameter:42.5mm; Lug-to-lug:46.0mm; Crystal: Hardlex with magnified glass; LumiBrite: LumiBrite on hands and index(es); Clasp: Three-fold clasp with push button release; Distance between lugs: 22; Water Resistance: 10 bar; Magnetic Resistance: 4,800 A/m; Weight: 161.0g; Functions: 24-hour hand (dual time display function); Stop second hand function; Date display; Features: Rotating bezel (24-hour display); Three-fold clasp with secure lock; See-through & Screw case back — retrieved 2026-09-22
- TUDOR official product page for reference M79470-0001 (Black Bay Pro; 39mm steel; fixed 24-hour bezel) - Case: 39mm steel case with polished and satin finish; Waterproofness: Waterproof to 200m (660 ft); Bezel: 24-hour graduated fixed bezel in satin-brushed steel; Dial: Black, domed; Crystal: Domed sapphire crystal; Movement: Manufacture Calibre MT5652 (COSC); self-winding mechanical movement with bidirectional rotor system; built-in architecture; Power Reserve: Power reserve of approximately 70 hours; Winding Crown: Screw-down winding crown in steel with the TUDOR rose in relief; Bracelet: Riveted steel bracelet with polished and satin finish, and TUDOR T-fit clasp with rapid adjustment; Guarantee: Five-year transferable guarantee with no registration or periodic maintenance checks required — retrieved 2026-09-23
Not affiliated with Seiko or TUDOR. Specifications are read from each manufacturer's own published documentation on the dates shown and may change; the manufacturer's current documentation governs.