Panerai Radiomir 1940 3 days Automatic Acciaio 42mm PAM 655

The Panerai Radiomir 1940 3 days Automatic Acciaio 42mm PAM 655 displays hours, minutes and small seconds. Its design language is influenced by historical timepieces and the brand’s relationship with the Italian Royal Navy. Carl Eady recently enjoyed hands on time with this beautifully simple, elegant but masculine timepiece.

This detailed review of the Panerai Radiomir 1940 3 days Automatic Acciaio 42mm PAM 655 includes live images, specification details and pricing.

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)


With product design, a key aspiration must surely be to create a style and form so unique that it is instantly recognisable, setting it apart from its contemporaries.  In the world of horology, one Italian brand has surely mastered this skill, creating watches of such distinction, beauty and simplicity that they are unmistakably ‘Panerai’.

Officine Panerai, founded by Giovani Panerai in Florence in 1860, opened its first premises on the Ponte alle Grazie in Florence.  It was not only a shop, ‘Orologeria G. Panerai & C.’  but a watch workshop and a school of horology. Over several transformational decades, the shop changed its name to ‘Orologeria Svizzera’ and relocated several times before finally settling in the Palazzo Arcivescovile in Piazza San Giovanni – where Panerai’s flagship store still proudly resides.

Perhaps the milestone which most firmly put Panerai on the map came in the early 20th century when an acknowledgement of faith in the brand resulted in a commission from the Italian Royal Navy to create nautical instruments, including mechanical depth gauges and compasses. It was during this period that Guido Panerai (one of Giovani’s grandsons) created ‘Radiomir’, a mixture of zinc sulphate and radium bromide with highly luminous (and radioactive) properties.  It was not initially developed for timepieces, but for making self-luminous sights. So effective was Radiomir that it became adopted for many uses where measurement in very poor light was required. 

It was not until 1935 that the Italian Navy commissioned the first divers watch from Panerai and in 1936 the company (at that time known as Guido Panerai & Figlio) produced the first prototype of a diver’s watch for a specialist unit known as ‘The Command of the 1st Submersible Group of the Navy’. The delivery of the first ten commissioned dive watches in 1938 resulted in Panerai becoming the official watch supplier to the Italian Navy, though credit should be afforded to Rolex for the movements in these early pieces.  In 1940, several improvements to the Radiomir were needed to meet the standards required by the Navy, mainly in strength and water resistance.  Today’s Radiomir 1940 retains many of the original design cues, however, the decades of refinement in material finish and movement design have resulted in a truly magnificent modern timepiece that, despite its diving credentials, offers elegance and sophistication.

The Case

Panerai stands out as being a brand synonymous with cushion shaped cases. The case execution of the Radiomir 1940 is first class.  Fashioned from the brands own AISI (American Iron and Steel Institute) 316L, it is a highly-polished steel-alloy case with anti-corrosive and hypoallergenic properties. A monobloc case construction means the lugs are part of the main case as opposed to the wire lugs used in early designs.  This enhances the diver’s watch look and masculinity of the timepiece.  From a side on view, the lines of the lugs follow the exquisite arc of the case. The 42mm diameter and height of 10.93mm are relatively conservative, making this a very wearable watch. The case provides a gorgeous housing for the purest of white dials.

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)

Unlike the Luminor range where the crowns sport the trademarked protective guard, the crown on the Radiomir 1940 is exposed and adorned with the ‘OP’ logo.  In keeping with the elegance of this timepiece, the crown is subtle and unobtrusive, arguably opening the brand to a wider audience.

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)

With sapphire crystals front and back, the owners are treated to a wonderful glimpse of the clever P.4000 movement.

The Dial and Hands

Less than 10% of the current collection of Panerai have white faces, and the Panerai Radiomir 1940 3 days Automatic Acciaio 42mm PAM 655 is the first and only white Radiomir 1940, making it something of a rarity. The ‘china white’ dial provides a stunning and pure backdrop for the rest of the dial estate.  The three luminous hands are sandy in colour and, in contrast to the simplicity of the hour and minute hands, there is a more decorative teardrop hand sweeping the seconds at 9 o’clock.

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)

Panerai’s curvaceous Arabic numerals adorn the perimeter, with a larger font gracing the 12, 3 and 6 o’clock positions.  Luminous dots also mark each hour in between and, whilst the overall dial is busier than many others in the brand’s stable, its rich DNA will no doubt delight Panerai’s army of loyal and passionate fans, known as the ‘Paneristi’.

The Movement

The 4Hz automatic P.4000 movement is executed entirely by Panerai at their Neuchâtel based Manufacture. At 31mm wide and 3.95mm deep, the P.4000 enables the Radiomir 1940 to have much more modest case dimensions than the Luminor. The slimness is, in part, due to the clever integration of an intriguing ‘offset’ micro rotor which sits flush within the movement. Adorned boldly with the brand name and the OP logo, this tungsten rotor efficiently winds the two series coupled spring barrels, delivering a full 3-day power reserve – a new minimum reserve for Panerai’s in house movements. 

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)

If one could further enhance this watch it would be to subtly display a reserve indicator on the back as Panerai have done with the P.4001 movement. Nevertheless, it is still a highly attractive movement and it is pleasing to see the detail rather than just having a solid steel case back. Although much of the movement is hidden, the balance remains in view with its wheel busily oscillating at 28,800 vph.  The finishing throughout is of a high standard, as one would expect from Panerai, with the large satin brushed plate offering fine contrast to the decorative colimaçon beneath the rotor.

The Strap 

With such an aesthetically striking watch, the strap choice is crucial.  Panerai has selected top quality ‘Assolutamente’ calf leather, a gorgeous untreated leather with a suede-like texture. Each strap is unique and has pale beige stitching to complement the deep spice brown leather tone.  The classic, almost vintage, appearance of the band is completed with a simple, yet tastefully satin-finished ‘pin and buckle’ fastening.

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)

Closing remarks

When first discovering the world of watches, Panerai is a brand which at first sight offers such distinct design attributes that one can’t help but feel admiration.  Rich in diver’s watch heritage, the brand has surprisingly only been on sale to the general public in the last 20 years.  In that time it has built a substantial and highly loyal fan base and, backed by the Richemont group, acquired its Neuchâtel based ‘Manufacture’ in 2002.

Image of Panerai Radiomir 1940 3 days Automatic Acciaio 42mm (PAM 00655)

Matching beautiful designs with movements of robust and refined quality can only enhance Panerai’s credibility and high standing. The Panerai Radiomir 1940 3 days Automatic Acciaio 42mm PAM 655 is tangible evidence of this and a truly eye-catching watch. The clarity and pureness is enriched by the china white face, which could arguably grace any occasion.  The clever combination of rustic and earthy tones, however, suggest that this is a timepiece ideally suited to wonderful leisurely days in the country, far away from urban madness.

Technical specification

  • Panerai Radiomir 1940 3 days Automatic Acciaio 42mm PAM 655
  • Calibre: P.4000 automatic
  • Power reserve: 72hr / 3 day
  • Case – Stainless Steel (AISI 316L)
  • Case size – 42mm
  • Glass – Sapphire crystal front and back
  • Water resistance: 100m / 10 BAR
  • Band – Assulomante Calf leather, Pin and Buckle fastening
  • Price – £8,000 (RRP as at 8.12.2016)

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