Arnold & Son Nebula Steel blue

Arnold & Son Nebula Steel blue

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Harmonious, radiant and intense, the Nebula’s skeleton movement reveals a structure in grey and blue tones. It combines steel with a PVD treatment on diametrically opposing bridges for a perfectly chic visual effect.  In addition to being the most symmetrical of Arnold & Son’s watches, it is ultra-thin, at just 8.73 mm. Available with a steel bracelet or a blue rubber strap, the Nebula 41.5 Steel radiates cool and intense elegance.

The first generation of the Nebula established its place in the House’s galaxy. Drawing on the legacy of John Arnold, a new star emerges to join this collection. The Arnold & Son Nebula 41.5 Steel introduces different colour treatments, new finishes, and new, even more powerful and attractive details.

Arnold & Son Nebula Steel blue

Inside and out

The name Nebula was chosen as a reference to the giant cloud of dust and gas in space. Some nebulas emerge from the gas and dust expelled when a dying star, like a supernova, explodes. Other nebulas are regions where new stars start to form. The seven bridges on the dial side of this timepiece radiate from the centre outwards, giving this sculptural movement the impression of a cosmic explosion.

Arnold & Son Nebula Steel blue

The Arnold & Son A&S5201 calibre was specially created for this piece and brings all of its character. It is set apart by its skeletonisation and almost perfect symmetry. The traditional shape of its bridges harks back to John Arnold’s chronometers and their openworked structure accentuates the feeling of lightness in a very mechanistic design.

Arnold & Son Nebula Steel blue


The bridges of the A&S5201 calibre are palladium-treated, giving a sheen that echoes the steel case. The main plate, barrel covers, and dial flange have been coloured with a blue PVD treatment. The Arnold & Son Nebula 41.5 Steel is fitted with either a three-link steel bracelet or a ballistic-type rubber strap with a woven-look surface. The two-tone aesthetic adorns the interior and exterior, the substance of the watch and the details. 

Arnold & Son Nebula Steel blue

Fully equipped

The Arnold & Son A&S5201 calibre was conceived as a skeleton mechanism instead of being modified by removing material.  The result is a completely clear and legible display on both sides. One by one, the components reveal their subtle finishes, adopting strict, fluid forms. The sum of these details and the overall approach make this calibre a special case in the exclusive circle of skeleton movements. For instance, it presents a total power reserve of 90 hours, only requiring it to be hand-wound every three-and-a-half days. At 4 mm thick, the calibre contributes to the piece’s overall slimness. The Nebula 41.5 Steel measures 8.73 mm thick, making it a natural member of the ultra-thin category.

Arnold & Son Nebula Steel blue

High altitude The A&S5201 calibre has also undergone several developments in addition to the new blue colouring. The balance wheel is now rhodium-plated to match the gear train and perfectly coordinate with the small seconds placed opposite. The main plate, particularly its reverse side, features “Rayons de la Gloire” finishes, a surface treatment similar to sunray-brushing in a wave shape. Arnold & Son rises magnificently to the challenge of sending its Arnold & Son Nebula 41.5 Steel into a new orbit.

  • Arnold & Son Nebula Steel blue
  • Arnold & Son Nebula Steel blue

Arnold & Son Nebula 41.5 Steel Blue Technical Specifications



  • hours, minutes, small seconds


  • Calibre A&S5201, hand-wound mechanical
  • Jewels: 24
  • Diameter: 31.50 mm
  • Thickness: 4.04 mm
  • Power reserve: 90 hours
  • Frequency: 3 Hz / 21,600 vph
  • Decoration
    • main plate: blue PVD, “Rayons de la Gloire” guilloché
    • barrels: blue PVD treatment and sunray-brushed
    • bridges: palladium treatment, polished angles and satin-finished surfaces
    • balance wheel: rhodium-plated
    • wheels: circular-grained and bevelled
    • screws: bevelled and mirror-polished heads


  • blue PVD flange, rhodium-plated appliqués


  • Material: stainless steel
  • Diameter: 41.50 mm
  • Thickness: 8.73 mm
  • Crystal: domed sapphire, anti-reflective on both sides
  • Case back: sapphire crystal, anti-reflective
  • Water-resistance_ 30 metres / 100 feet


  • Material: stainless steel or blue “ballistic” rubber
  • Buckle: folding clasp or pin buckle, stainless steel

Retail price Switzerland       

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