TUDOR Pelagos M25600TN-0001: specifications and what to check

Titanium and steel, not titanium

The material line on this reference reads 42mm titanium and steel case with satin finish, and the clasp is specified as folding clasp and safety catch in steel.

So this is a mixed-material watch. The Pelagos 39 is grade 2 titanium throughout, including its crown; this one is not.

That distinction gets flattened constantly in listings, usually into "titanium Pelagos". It matters for three reasons.

Weight. Steel components in a titanium watch change what it feels like, and weight is the property a buyer registers first.

Wear. The two metals mark differently — steel takes bright fine hairlines, titanium a duller broader scuff — so a single condition grade across the whole watch is the wrong tool. Assess the titanium parts against titanium and the steel parts against steel.

Parts. A clasp specified in steel is not interchangeable with a titanium one, and vice versa.

Write what TUDOR writes.

The valve at nine o'clock

Water resistance is 500 metres, and the crown specification carries a second element: a helium escape valve at 9 o'clock.

That valve exists for saturation diving. Helium works into a case under prolonged pressure, and on ascent the pressure inside can exceed the pressure outside — which is what pushes crystals off watches never designed for it. The valve vents it.

For inspection, the point is simply that it is a functional component on the side of the case, not an ornament. Find it. Confirm it is present, that it sits flush, and that the surrounding case shows no damage or evidence of tampering.

A missing or replaced valve on a 500-metre watch is a serious finding, and it is not something a seller's photographs are likely to show clearly.

A patented extension inside the clasp

TUDOR specifies a bracelet extension system developed and patented by TUDOR, inside a steel folding clasp with a safety catch.

Unlike the toolless T-fit used on newer references, this is a sprung mechanism designed to let the bracelet take up length over a suit. It lives inside the clasp where nobody looks.

Exercise it. Extend it fully, let it return, and repeat. It should move smoothly and hold at its limits rather than collapsing under load. Then close the safety catch and confirm it latches with a definite click.

At 500 metres on a titanium bracelet this is the assembly holding the watch on, and it is the one component whose failure loses the watch entirely.

What the rating means on a used watch

500m (1,640 ft) describes the case as TUDOR builds it.

Nothing about the example on your bench confirms it. Seals age and harden; a case that has been opened was resealed by a hand you never watched; nobody has run a pressure test.

Quote it as a specification and either have the watch tested or say clearly that it has not been. That is a stronger position than silence, and far stronger than repeating a factory figure as though you had verified it.

Bezel, dial and movement

The bezel is titanium, unidirectional, graduated over 60 minutes with a ceramic matt black disc and white luminescent graduations. Test it as a safety component: clockwise should do nothing at all, anticlockwise should click cleanly through a full revolution.

The dial is black with white index and a date at 3 o'clock — worth noting against the Pelagos 39, which has no date.

The movement is the Manufacture Calibre MT5612, COSC certified, with approximately 70 hours of reserve, and TUDOR publishes a five-year transferable guarantee with no registration or periodic checks required.