MB&F · Horological Machines

Strap for Horological Machine N°3 HM3 Megawind Red Gold

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

Lug width20 mm
Case diameter47 mm
Reference35.RTL.B
FamilyHorological Machines
MovementMB&F caliber HM3 Hours, Minutes, Day / Night Indication | Date | Power Reserve Indicator
CaseTitanium, Red Gold

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Horological Machines 35.RTL.B

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Horological Machines 35.RTL.B, seen from the bench

The MB&F Horological Machine N°3 (model 35.RTL.B) features a 47 mm case available in titanium and red gold, with a 20 mm lug width. It houses the automatic MB&F HM3 caliber offering hours, minutes, day/night function, date, and power reserve indicator. The three-dimensional architecture exposes the movement as a mechanical sculpture, with the case design proportioned to accommodate the complex movement and ensure ergonomic compatibility with various leather straps.

Frequently asked questions

What is the lug width of the MB&F Horological Machines 35.RTL.B?

The 35.RTL.B features a lug width of exactly 20 millimetres. This measurement is critical when purchasing compatible straps: measure by positioning a digital calliper between the spring bar pins where the strap attaches to the case. Even minimal discrepancies result in construction incompatibility.

What is the best strap for the MB&F Horological Machines 35.RTL.B?

Selection depends on intended use and aesthetic preference. Alligator leather with natural tanning complements the case's sculptural character, emphasising three-dimensional texture. Shell cordovan develops patina that evolves over time, acquiring depth that mirrors metal ageing. Vegetable-tanned calf represents the compromise between elegance and daily durability. Nylon NATO offers versatility for those who wear the timepiece as an active instrument.

How do I change the strap on the MB&F Horological Machines 35.RTL.B?

Extract the case spring bars using a spring bar tool (specialised implement with a thin, forked tip). Position the tip beneath the pin, applying inward pressure toward the case: the pin releases. Remove the old strap and align the new one to the holes, then reinsert the pin until the locking click occurs. A delicate operation requiring care to avoid scratching the titanium or rose gold case.

Can I use an aftermarket compatible strap on the 35.RTL.B?

Yes, provided the strap is constructed for a 20-millimetre lug width. Artisanal straps from milanostraps.it are manufactured with precise construction tolerances, guaranteeing compatibility without excessive play. Artisanal quality ensures the strap behaves as a natural extension of the case, not as a detached component.

What is the lifespan of a leather strap on the MB&F Horological Machines 35.RTL.B?

Lifespan varies according to material and usage patterns. Alligator with natural tanning resists 3-4 years under daily wear, developing patina. Shell cordovan can achieve 5-6 years before replacement becomes necessary, owing to superior molecular density. Vegetable-tanned calf lasts 2-3 years under frequent stress, yet evolves aesthetically throughout its lifecycle. FKM rubber exceeds 4 years without significant degradation.

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.

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