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Tudor · Black Bay

Tudor Black Bay 36

Reference M79640-0002 · Classic · 36 mm

Specifications

Reference
M79640-0002
Family
Black Bay
Category
Classic
Status
Current
Case material
Stainless steel
Case diameter
36 mm
Case thickness
10.5 mm Official
Lug-to-lug
43.9 mm Third-party
Lug width
19 mm Official
Water resistance
100 m
Bezel
Fixed, smooth
Certifications
COSC
Calibre
MT5400 Official
Power reserve
about 70 h

Official product page · retrieved October 14, 2026

Does it fit your wrist?

Enter your wrist circumference. The watch appears to scale on the flat top of the wrist.

Lug-to-lug 43.9 mmFlat top of the wrist 54.1 mm
Top view on a wrist, to scale
Flat top of the wrist 54.1 mmLug-to-lug 43.9 mmCase diameter 36 mm
Side view, across the wrist

Comfortable

Lug-to-lug 43.9 mm on a flat top of 54.1 mm: 81 % of the width.

Lug-to-lug is 75 to 95% of the flat top, the usual comfortable range.

Measurements and sources

Brands rarely publish thickness, lug width and lug-to-lug together. Each observation below is kept separate, with who gave it.

Case thickness

Value Type Source Date
10.5 mm Official Tudor October 14, 2026

Lug-to-lug

Value Type Source Date
43.9 mm Third-party Everest Bands Strap retailer size guide (December 2023), model-level figure listed for refs 79640, 79643. October 14, 2026

Lug width

Lug width is the gap between the lugs, where the strap fits. It is not lug-to-lug.

Value Type Source Date
19 mm Official Tudor October 14, 2026

Calibre source

Official Tudor · retrieved October 14, 2026

Other versions in the same case

These references differ only by dial, bracelet or bezel colour. The brand gives them the same case dimensions, so the figures on this page apply to them too.

Other Black Bay references

Watch Ø Thickness Lug-to-lug Calibre
Black Bay M7941A1A0NU-0003 41 mm 12.7–13.6 mm⚠ 49–50 mm⚠ MT5602-U
Black Bay Ceramic M7941A1ACNU-0001 41 mm 13.6 mm 49 mm MT5602-U
Black Bay 31 M79600-0001 31 mm 9.5 mm 37.8 mm MT5201
Black Bay 39 M79660-0002 39 mm 12 mm 47.3 mm MT5602
Black Bay 41 M79680-0002 41 mm 12.2 mm 50.2 mm MT5601

Same brand in the data set

Watch Ø Thickness Lug-to-lug Calibre
1926 28 M91350-0011 28 mm 9.1 mm — T201
1926 36 M91451-0011 36 mm 9.2 mm — T601
1926 39 M91551-0009 39 mm 9.2 mm — T601
1926 Luna M91560-0002 39 mm 10.1 mm — T607-9
1926 M91650-0001 41 mm 9.3 mm — T601
Black Bay 54 M79000B-0001 37 mm 11.2 mm 45.8 mm MT5400
Black Bay 58 M7939A1A0NU-0002 39 mm 11.7 mm 47.8 mm MT5400-U
Black Bay 58 GMT M7939G1A0NRU-0001 39 mm 12.8 mm — MT5450-U
Black Bay 58 925 M79010SG-0002 39 mm 12.7 mm 47.8 mm MT5400
Black Bay 58 Bronze M79012M-0001 39 mm 11.9 mm 47.8 mm MT5400
Black Bay 68 M7943A1A0NU-0001 43 mm 13.6 mm — MT5601-U
Black Bay Bronze M79250BA-0001 43 mm 14.6 mm 52.7 mm MT5601
Black Bay Chrono M79360N-0014 41 mm 14.4 mm 50 mm MT5813
Black Bay GMT M79830RB-0001 41 mm 14.6 mm 50 mm MT5652
Black Bay Pro M79470-0004 39 mm 14.6 mm 47.2 mm MT5652
Monarch M2639W1A0U-0001 39 mm 11.9 mm — MT5662-2U
Northflag M9140G1A0U-0001 40 mm 12.7 mm — MT5652-U
Pelagos Ultra M2543C1A7NU-0001 43 mm 14.5 mm — MT5612-U
Pelagos 39 M25407N-0001 39 mm 11.8–12.2 mm⚠ 47 mm MT5400
Pelagos 42 M25600TB-0001 42 mm 14.3 mm 50 mm MT5612
Pelagos FXD GMT M2542GXX7NU-0002 42 mm 12.7 mm — MT5652-U
Pelagos FXD M25717N-0001 42 mm 12.8 mm 52 mm MT5602
Pelagos FXD Chrono M25827KN-0001 43 mm 13.2 mm 52 mm MT5813
Ranger 36 M79930-0007 36 mm 11 mm — MT5400
Ranger M79950-0001 39 mm 12 mm 47 mm MT5402
Royal 36 M2836C1A0-0102 36 mm 9.7 mm — MT5412
Royal M2840D1A0-0001 40 mm 11.4 mm — MT5633

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