Tudor · Black Bay 58

Strap for Black Bay 58 GMT Stainless Steel / Black / Bracelet

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter39 mm
Reference7939G1A0NRU-0001 (aka: M7939G1A0NRU-0001)
FamilyBlack Bay 58
MovementTudor caliber MT5450-U Hours, Minutes, Seconds, Additional 24 Hour Hand (adjustable) | Chronometer
CaseStainless Steel

Spring bar

Spring bars for Tudor

The right category for this model · choose the 20 mm size

Straps for the Black Bay 58 7939G1A0NRU-0001 (aka: M7939G1A0NRU-0001)

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Black Bay 58 7939G1A0NRU-0001 (aka: M7939G1A0NRU-0001), seen from the bench

The Black Bay 58 represents the Tudor reinterpretation of the classic dive watch with GMT influences. It mounts the automatic caliber MT5450-U with chronometer certification and GMT function via an adjustable 24-hour hand. 20mm lugs complete the technical configuration of the model.

Frequently asked questions

What is the lug width of the Tudor Black Bay 58 7939G1A0NRU-0001?

The lug width of the Tudor Black Bay 58 7939G1A0NRU-0001 is 20 millimetres. This dimension is specific to this compact variant and requires custom-made straps. Measure the distance between the two lugs of the case to verify compatibility before ordering.

Which strap is best suited for the Tudor Black Bay 58 7939G1A0NRU-0001?

We recommend alligator straps with vegetable tanning (dark brown or cognac), shell cordovan for those desiring luxury and natural patina, or vegetable-tanned calf for daily versatility. For regular diving, FKM rubber or NATO cordura straps guarantee maximum water resistance.

How do I change the strap on the Tudor Black Bay 58 7939G1A0NRU-0001?

Obtain a spring bar tool with two flat ends. Position it beneath the spring of the lug hinge, lift gently to create space, then extract the spring. Repeat on the other side, then replace the strap by inserting the spring into the new strap. If inexperienced, consult a professional watchmaker.

Is an aftermarket strap compatible with the Tudor Black Bay 58 7939G1A0NRU-0001?

Yes, any strap with 20mm lug width is compatible with the Black Bay 58. Always verify specifications before purchasing. We recommend artisanal straps of premium quality, crafted with fine leather and finished with care, to preserve the watch's value and aesthetics.

How long does a leather strap last on the Tudor Black Bay 58?

A quality leather strap (alligator or shell cordovan) typically lasts 3-5 years with regular use, depending on care and moisture exposure. Leather requires periodic maintenance: avoid prolonged submersion, dry it after immersion, and apply protective balms every 6-12 months. Rubber straps last 5-7 years before requiring replacement.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

Request an appointment →

Casati Milano · Via XX Settembre 15, Milan · by appointment only