Hamilton · Railroad

Strap for Railroad 40 Auto Stainless Steel / Black

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

Lug width20 mm
Case diameter40 mm
ReferenceH40555731
FamilyRailroad
MovementHamilton caliber H-10 hours, minutes, seconds | date
Year2016
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

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

Straps for the Railroad H40555731

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Railroad H40555731, seen from the bench

The Hamilton Railroad H40555731 is a contemporary evolution of American railroad watchmaking tradition, featuring a 40mm stainless steel case with satin finish and a 20mm lug width. Powered by the automatic Hamilton caliber H-10 movement, it beats at 28,800 vibrations per hour with an 80-hour power reserve and date complication at 3 o'clock. The functional dial design prioritizes legibility with baton indices, while the screw-down crown and pronounced shoulder casing ensure robust construction. The 20mm lug width defines compatibility with a broad range of straps and bracelets.

Frequently asked questions

What is the lug width of the Hamilton Railroad H40555731?

The Hamilton Railroad H40555731 features a lug width of 20mm. This measurement determines strap compatibility and must match precisely the metal bars connecting the case to the strap. Any watch strap with 20mm lug width is compatible with this model.

Which strap is recommended for the Hamilton Railroad H40555731?

For the H40555731, leather straps in aniline, alligator, or shell cordovan are ideal, enhancing the watch's refined character. Alternatively, acrylic NATO or FKM rubber preserve its heritage as a tool watch. Your choice depends on use: leather for formal contexts, NATO or rubber for sporadic or active wear.

How do I change the strap on my Hamilton Railroad H40555731?

To change the strap on the Railroad H40555731, you must remove the lugs (metal bars) from inside the case. Using a spring bar tool, apply pressure to the internal elastic bar until the end disengages from the groove. Handle with care to avoid scratching the case. If inexperienced, consult a professional watchmaker.

Can I fit an aftermarket quality strap on my Hamilton Railroad?

Yes, the H40555731 is fully compatible with aftermarket straps provided they respect the 20mm lug width. Makers such as Casati Milano offer bespoke leather straps commissioned specifically for this width, guaranteeing precision in lug attachment and superior construction quality.

How long does a leather strap last on the Hamilton Railroad H40555731?

A quality leather strap on the H40555731 typically lasts three to five years with daily wear. Noble materials such as shell cordovan or vegetable-tanned leather can exceed a decade. Longevity depends on usage frequency, ambient humidity, and maintenance (periodic cleaning and leather conditioning).

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