Hanhart MAD Preventor HD12 In Black Forest Green Goes Compact

There is a certain honesty to a watch designed to be used rather than merely admired. For Hanhart, that philosophy has been part of the brand’s identity since its foundation in 1882, with precision, legibility, reliability and durability at the heart of its mechanical timepieces.

Now, in collaboration with British watch enthusiast Russell, better known as the MAD Watch Collector, Hanhart has taken its robust Preventor HD12 and given it a new, more compact character. The MAD Preventor HD12 arrives for the first time in a 36 mm case, combining the hard-wearing credentials of Hanhart’s HD12 construction with a distinctive Black Forest green dial.

Limited to just 200 pieces, it is a watch that feels deliberately purposeful: compact enough for everyday wear, sufficiently robust for outdoor use, and unmistakably rooted in Hanhart’s German heritage.

A Preventor For A New Generation

The Preventor HD12 has always been about resilience. Its name and construction reflect Hanhart’s determination to create a watch capable of accompanying its wearer through everyday life without demanding excessive care or attention.

The new 36 mm interpretation responds directly to repeated requests for a smaller version. The reduced diameter gives the Preventor a more classic proportion while retaining the strong visual identity of the original model.

Interestingly, the 20 mm lug width has been retained at Russell’s suggestion. The result is an unusual but convincing combination: a compact 36 mm case with relatively broad lugs, giving the watch presence on the wrist while maintaining balanced proportions. It also opens up considerable versatility when it comes to straps.

Black Forest Green

Colour is perhaps the most immediately distinctive element of the MAD Preventor HD12. The matte Black Forest green dial is a direct reference to Hanhart’s home in Gütenbach, in the Black Forest of Germany. Rather than a bright or highly polished green, the matte finish reinforces the watch’s utilitarian character, allowing the colour to become part of its identity without compromising its functional purpose.

The historic Hanhart logo appears on the dial, while luminous numerals and hands ensure the clarity expected from a watch conceived around legibility. Super-LumiNova® C3 X2 GL coats the numerals, cathedral hands and seconds hand, providing strong visibility both during the day and in low-light conditions.

The overall effect is restrained, highly legible and distinctly German: nothing is present simply for decoration.

Built To Resist

Beneath the restrained exterior lies one of the most interesting aspects of the Preventor HD12: Hanhart’s proprietary HD12 steel.

The material is engineered to provide an exceptional level of surface hardness while retaining the corrosion resistance of stainless steel. The case combines a multi-stage surface-hardening process with a transparent hard PVD coating, resulting in a surface hardness of up to 1,200 HV on the Vickers scale. For comparison, conventional 316L stainless steel has a surface hardness of around 220 HV.

The significance is practical rather than purely technical. Instead of simply coating the steel, Hanhart first diffuses large quantities of carbon into the stainless steel, creating a gradual transition between the hardened exterior and softer core. This helps avoid the brittleness that can accompany a simple surface coating.

The result is a case designed to withstand the knocks and scratches of everyday life while preserving its combination of brushed, matte and polished surfaces. For a watch intended to be worn rather than kept behind glass, that makes considerable sense.

Classic Proportions, Modern Construction

The 36 mm case measures just 10.50 mm in height, with a lug-to-lug measurement of 43 mm. A smooth bezel surrounds a domed sapphire crystal with anti-reflective coating on its inner surface, while the screwed case back and screw-down crown contribute to the watch’s practical credentials. Water resistance is rated to 15 bar, or 15 ATM, in accordance with DIN 8310.

The crown itself carries Hanhart’s historic ‘h’, a small but significant reminder of the brand’s long history of functional watchmaking. It is an interesting juxtaposition: the proportions are distinctly traditional, but the materials and engineering are thoroughly contemporary.

Everyday Engineering

The steel bracelet continues that theme. Equipped with quick-release spring bars, it can be removed and replaced without tools, while the folding clasp incorporates tool-free fine adjustment. This allows the wearer to make small adjustments throughout the day as the wrist changes size with temperature and activity.

For those who prefer a more traditional appearance, the watch is also available on calfskin with an Alcantara lining. Black, dark brown and light brown options provide further flexibility. In either configuration, the 20 mm lug width makes the watch particularly adaptable.

A Proven Mechanical Heart

Inside the MAD Preventor HD12 is the Sellita SW200-1, a proven automatic calibre chosen for its robustness and reliability. The movement operates at 28,800 vibrations per hour, or 4 Hz, and provides at least 38 hours of power reserve. It offers hours, minutes and central seconds, with hacking seconds for precise time-setting, while deliberately dispensing with a date display.

That last detail is worth noting. The absence of a date aperture keeps the Black Forest green dial clean and symmetrical, reinforcing the watch’s emphasis on essential information.

Hanhart regulates every movement at its manufacture in Gütenbach according to its own accuracy requirements. Averaged across six positions, the stated daily rate is between 0 and +8 seconds, with Hanhart not permitting the watch to run slow in its principal positions. It is an approach entirely consistent with the brand’s long-standing philosophy.

Hanhart: Measuring Time

Since 1882, Hanhart has built its reputation around precision instruments with a purpose. The company played an important role in the history of German watchmaking, particularly through its development of wrist chronographs and stopwatches.

That heritage continues to inform the brand’s contemporary watches. Technical inventiveness is combined with an emphasis on precision, legibility, straightforward operation and longevity.

The MAD Preventor HD12 is therefore not an exercise in nostalgia. Its historic logo and Black Forest green dial may connect it directly to Hanhart’s origins, but it’s hardened HD12 steel, sapphire crystal, modern automatic movement and practical bracelet are firmly contemporary. Perhaps that is what makes the collaboration particularly successful.

A Watch Made To Be Worn

At 36 mm, the MAD Preventor HD12 occupies an increasingly interesting space in contemporary watchmaking. It is compact without being delicate, traditional without being old-fashioned, and technically sophisticated without sacrificing simplicity.

The Black Forest green dial gives it a character all of its own, while the unusual combination of a 36 mm case and 20 mm lugs provides both visual presence and strap versatility. Limited to only 200 pieces, it is also a relatively rare interpretation of Hanhart’s Preventor HD12.

For collectors, the appeal lies in the combination of provenance, practicality and individuality. For everyone else, it is simply a well-engineered mechanical watch designed to go wherever its owner does. And perhaps that is the greatest strength of the MAD Preventor HD12: it does not ask to be treated as a precious object. It asks to be worn.

Technical Specifications:

Hanhart MAD Preventor HD12

• Case: 36 mm hardened HD12 steel
• Thickness: 10.50 mm
• Lug-to-lug: 43 mm
• Lug width: 20 mm
• Crystal: Domed sapphire with inner anti-reflective coating
• Water resistance: 15 ATM
• Dial: Matte Black Forest green
• Movement: Sellita SW200-1 automatic
• Frequency: 28,800 vph / 4 Hz
• Power reserve: At least 38 hours
• Accuracy: Hanhart regulation of 0 to +8 seconds per day, averaged across six positions
• Bracelet: Hardened stainless steel with quick-release spring bars and tool-free fine adjustment
• Alternative strap: Calfskin with Alcantara lining
• Edition: Limited to 200 pieces
• Price: €1,140 including 19% VAT on calfskin; €1,340 including 19% VAT on steel bracelet
• Delivery: From approximately the end of October 2026

For more information please visit Hanhart