Mark 5

Serial Number Range: 50xxxxx – 59xxxxx

General Notes: The Mark 5 dial is made of three subtypes, the Mark 5, 5A, and 5B. The serial ranges all seem to be similar, and they are all very close in appearance, so they are considered part of the same iteration. The Mark 5 dial is much more common than the A or B, hence it’s place in the set. Some much earlier serials – without a distinct range – have been seen with Mark 5 dials so they likely doubled as an early service dial for earlier 1675s that were serviced in the middle and late 1970’s. It is not, however, the common service dial.

Distinguishing Characteristics:

  • The best way to characterize any Mark 5 dial is to look at the M in ‘Master’ and the CH in ‘Chronometer.’ The right vertical bar of the M bisects the C and H, while on all other dials (especially the Mark 4, which is visually similar) the right side of the M falls somewhere on top of the C. This carries over to the R in ‘Master,’ the left vertical bar of which falls right over the M in ‘Chronometer.’
  • The ‘Rolex’ text is generally stretched wider, which can be seen on the O, which is more oval, and the E, which has longer top and bottom bars.
  • The coronet bases of the Mark 5 iterations fall between the Mark 4 and 6 in that the Mark 4 dial has a thin opening and the Mark 6 a clear oval; the Mark 5’s are consistently between those two extremes.
  • Further characteristics are delineated in the subtypes, below.

Subtypes: The common distinguishing Mark 5 characteristics are above, the differences between subtypes are listed below.

Mark 5A vs 5:

  • On the 5A dial, as compared to the 5, the top half of the R in ‘Rolex’ (the D part) more clearly overhangs the right drop leg (the \ part).
  • slender-based coronet, a wider top to the A of ‘GMT-Master,’ and slight changes in the font spacing.
  • The Mark 5 dial is make by Beyeler and the 5A is made by Lemrich – see the dial page for their respective dial backs.

Mark 5B vs 5 & 5A:

  • The 5B dial has a widened ‘Rolex’ that looks stretched horizontally compared to the dial subtypes above.
  • The shape of the O throughout the SCOC text are round on the 5B and tall ovals on the 5 and 5A.
  • The lower horizontal bars of the F’s in the SCOC text are longer than the above dials.


Picture Credit: HQ Milton, Lucky from IG