In all-steel 37 mm form, the silver-toned dial exists only as an anniversary reference. Audemars Piguet issued the plain steel 15550 with four dials for the fiftieth anniversary and carried only three of them into standard production, and silver-toned is the one that did not continue. A buyer wanting a pale dial in this size without the anniversary designation is directed instead to the two-tone version, which pairs a steel case and bracelet with a rose gold bezel and rose gold links, so the standard route to silver-toned at 37 mm changes the metal rather than keeping it. That makes this reference the only way to have the combination in steel throughout. It is also the most conservative dial the size offers, closer to a mid-century watch than to the sports watch the Royal Oak is usually taken for, and in a plain steel case with no setting anywhere it is the quietest reference in the entire 37 mm anniversary line.
The case is 37 mm across and 9.1 mm thick in stainless steel, with the plain octagonal bezel carrying the eight exposed hexagonal screws that have identified the Royal Oak since 1972, secured from the caseback so the visible heads sit true and aligned. Brushed surfaces meet polished chamfers on every edge of case and bezel, with the transition falling exactly on the line rather than near it, and in steel that boundary holds a harder and cooler edge than gold produces. The dial is silver-toned with the Grande Tapisserie pattern, the larger of the two grids the collection uses. On a pale ground the tapisserie reads as fine relief rather than as shadow, since there is no dark field for the recesses to fall into, and the grid is picked out only by the difference between the brushed square tops and their cut edges. That is a more demanding surface to produce than a dark one, because any inconsistency in the cutting shows where black would have concealed it. White gold applied hour-markers and Royal Oak hands sit above it. The bracelet is integrated steel, tapering from the case with the same alternation of brushed and polished surfaces, and closes on an AP folding clasp.
The function set is hours, minutes, centre seconds and a date. That is the standing configuration the Royal Oak has carried since the original, and this reference makes no departure from it. Centre seconds keeps all three hands on one axis and the date sits within the dial rather than at its edge. Silver-toned with white gold markers gives moderate contrast rather than strong, which is characteristic of any pale dial with cool metal above it, and the applied markers do most of the work the colour cannot. In practice it is legible without being emphatic, which is consistent with everything else about the reference. A pale dial also holds its appearance across the day more steadily than a dark one, since there is no deep ground for shadow to gather in and the surface changes with the light rather than against it.
The Royal Oak is the collection Audemars Piguet is built on, and the 37 mm anniversary references form a three-step ladder in setting. This reference is the base of it, unset at 9.1 mm. The diamond-set version holds the same height, since bezel stones sit in metal that already existed. The fully gem-set version sets dial, bezel and bracelet in a single coloured stone and reaches 10 mm. Across the plain steel references the dials are silver-toned, Bleu nuit nuage 50, grey and light blue, and the standard-catalogue continuation carries the last three. The diamond-set steel references drop silver-toned as well, running light blue, Bleu nuit nuage 50 and grey, while the diamond-set rose gold references pick the colour back up alongside Bleu nuit nuage 50 and khaki green.
This reference suits a collector who wants a Royal Oak with nothing added to it. No setting, no two-tone, no colour, in the smaller of the two main sizes and the more classical of the dials. That is a narrow specification and the anniversary designation is the only thing about the watch that is not entirely plain. For a collector who values the case as the argument, that is the point rather than a limitation, since the tapisserie on a pale dial and the brushed and polished alternation on the case are both harder to execute than their darker and warmer equivalents and both are more visible here than anywhere else in the line. It appeals to someone who has decided against the gold references and against the set ones, and who wants the dial that will look the same in twenty years as it does now. Steel throughout also means the watch wears without the caution a gold bracelet invites, which matters more at 37 mm than at 41 mm because the smaller bracelet sits tighter and takes more contact. The anniversary designation ties production to the occasion.
