TUDOR · Black Bay 58 and Black Bay
TUDOR M7939A1A0NU-0001 vs TUDOR M7941A1A0NU-0001
11 published specifications differ between these two, and 4 are identical. Every figure below is what the manufacturer states for that reference; nothing is inferred from the other watch.
What differs
| Specification | TUDOR Black Bay 58, 39mm steel on braceletM7939A1A0NU-0001 | TUDOR Black Bay 41, steel on braceletM7941A1A0NU-0001 |
|---|---|---|
| Case | 39mm stainless steel case with polished and satin finishes | 41mm steel case with polished and satin finish |
| Diameter | 39 mm | 41 mm |
| Thickness | 11.7 mm | 13.6 mm |
| Lug width | 20 mm | 21 mm |
| Bezel | Unidirectional rotatable bezel in stainless steel with anodised aluminium insert | 60-minute unidirectional bezel in stainless steel with black aluminium insert |
| Dial | Matt black, domed, with applied hour markers | Black, domed, with silver-coloured applied hour markers |
| Crown | Stainless steel screw-down winding crown with the TUDOR rose in relief | Stainless steel screw-down crown with the TUDOR rose in relief |
| Bracelet | 5-link stainless steel bracelet with polished and satin finishes | 3-link stainless steel bracelet with polished and satin finish |
| Calibre | Manufacture Calibre MT5400-U | Manufacture Calibre MT5602-U |
| Power reserve | 65-hour power reserve | 70-hour power reserve |
| Certification | COSC and METAS certified | COSC and METAS certified (Master Chronometer) |
What is identical
Worth knowing as much as the differences: these are the specifications you cannot use to tell the two apart.
- Water resistance
- Waterproof to 200m (660 ft)
- Crystal
- Domed sapphire crystal
- Clasp
- TUDOR "T-fit" clasp
- Movement
- Self-winding mechanical movement with bidirectional rotor system
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.
| Movement notes | not stated | METAS certification covers precision certified by COSC, waterproofness to 200m under the ISO standard, smooth functioning in a 15,000 gauss magnetic field, and the 70-hour power reserve. |
|---|
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.
These reach different buyers
41 mm on the M7941A1A0NU-0001 against 39 mm on the M7939A1A0NU-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.
A visible difference in how they wear
1.9 mm of thickness separates these, with the M7941A1A0NU-0001 the taller at 13.6 mm. That is the difference between a watch that goes under a cuff and one that catches on it — worth a photograph from the side rather than a number in a table.
Different movements to verify and to service
The M7939A1A0NU-0001 runs the Manufacture Calibre MT5400-U and the M7941A1A0NU-0001 the Manufacture Calibre MT5602-U. Two consequences at intake: the service history that is normal for one calibre is not evidence about the other, and the calibre is the check that catches a movement swapped into the wrong case. Confirm the movement matches the reference rather than assuming it from the dial.
What to check on each
M7939A1A0NU-0001
- Verify the calibre is MT5400-U rather than an earlier MT5402. The Master Chronometer version is a different movement, and the two are easy to conflate in a listing written from memory.
- Inspect the anodised aluminium bezel insert closely. Aluminium marks in a way ceramic does not, and insert condition is one of the larger swings in desirability on this reference.
- Work the five-link bracelet's T-fit clasp through its adjustment range, and check the links for stretch at the pins.
M7941A1A0NU-0001
- Check the T-fit clasp actually adjusts. It is the headline convenience of this generation, and a clasp that has been forced or badly serviced is an expensive part to put right.
- Read the bezel action. TUDOR states it is deliberately harder to turn at the 12 o'clock position to prevent inadvertent rotation — a bezel that spins freely there has been apart.
- Confirm the calibre against the reference. MT5602-U is the Master Chronometer version; earlier Black Bay generations use different movements, and the caseback and papers should agree with what is inside.
Sources
- TUDOR official product page for reference M7939A1A0NU-0001 (Black Bay 58; 39mm steel case; steel bracelet) - Case: 39mm stainless steel case with polished and satin finishes; Lugs: 20mm lug width; Case thickness: 11.7mm; Waterproofness: waterproof to 200m (660 ft); Bezel: unidirectional rotatable bezel in stainless steel with anodised aluminium insert; Dial: matt black; domed; with applied hour markers; Crystal: domed sapphire crystal; Movement: Manufacture Calibre MT5400-U (COSC and METAS certified); self-winding mechanical movement with bidirectional rotor system; Power Reserve: 65-hour power reserve; Winding Crown: stainless steel screw-down winding crown with the TUDOR rose in relief; Bracelet: 5-link stainless steel bracelet with polished and satin finishes with TUDOR T-fit clasp; the unidirectional rotatable bezel rotates in one direction only and is deliberately harder to turn when the zero marker is at 12 o'clock to avoid inadvertent rotation — retrieved 2026-09-22
- TUDOR official product page for reference M7941A1A0NU-0001 (Black Bay; 41mm steel case; steel bracelet) - watch specifications as published by Montres TUDOR SA - Case: 41mm steel case with polished and satin finish; Lugs: 21mm lug width; Case thickness: 13.6mm; Waterproofness: waterproof to 200m (660 ft); Bezel: 60-minute unidirectional bezel in stainless steel with black aluminium insert; Dial: black; domed; with silver-coloured applied hour markers; Crystal: domed sapphire crystal; Movement: Manufacture Calibre MT5602-U (COSC and METAS certified); self-winding mechanical movement with bidirectional rotor system; Power Reserve: 70-hour power reserve; Winding Crown: stainless steel screw-down crown with the TUDOR rose in relief; Bracelet: 3-link stainless steel bracelet with polished and satin finish with TUDOR T-fit clasp; the page also states a five-year guarantee and describes METAS Master Chronometer certification as covering precision certified by COSC; waterproofness to 200 m in accordance with ISO standard; smooth functioning when exposed to a magnetic field of 15000 gauss; and a 70-hour power reserve; the unidirectional rotatable bezel rotates in one direction only and is deliberately harder to turn when the zero marker is at 12 o'clock to avoid inadvertent rotation — retrieved 2026-09-22
Not affiliated with TUDOR. Specifications are read from each manufacturer's own published documentation on the dates shown and may change; the manufacturer's current documentation governs.