Titanium has become a prominent material in Garmin’s premium watches because it is lighter than stainless steel and stronger than aluminium. However, using it throughout a watch case creates a major technical challenge: metal can block the radio signals needed for Bluetooth, LTE, satellite communications, ANT+, NFC and Wi-Fi.

That is why the standard Fenix 9 uses a polymer sidewall alongside titanium components such as the bezel and backplate. Garmin says a completely metal case would prevent signals from entering or leaving the watch, while simply adding polymer sections would require multiple gaskets. Those seals would increase the thickness of the case and compromise its design.

Garmin COO Brad Trenkle described the result as a balance between signal transmission, water resistance and size. The company needed polymer areas for connectivity, but also wanted to avoid the bulky appearance associated with earlier designs such as the Forerunner 201.

For the Fenix 9 Pro and Marq Generation 3, Garmin uses a process called nano molding, or NMT. According to Garmin Creative lead for Outdoor, Todd Register, the method bonds polymer and titanium at the nanoscale rather than relying on conventional adhesive or the same gasket arrangement.

The titanium is first etched with an extremely fine texture. This creates an interlocking surface that allows the polymer to bond directly to the metal. Garmin says the resulting connection is rigid enough to accommodate the antennas while keeping the case thinner than previous approaches.

The company demonstrated the process using a magnified image of titanium during the Marq Generation 3 launch. Although the untreated surface appears almost completely smooth, etching creates a texture that enables the polymer and metal to lock together at microscopic level.

Nano molding is not entirely new in consumer electronics, but its use in Garmin’s watch range helps explain why full-metal models remain concentrated in the more expensive Fenix 9 Pro and Marq Generation 3 lines. The process could potentially benefit other series, although applying it to a less expensive range would also raise questions about pricing.

Garmin’s Venu line is mentioned as one possible candidate for a future all-titanium design. The current Venu 4 still has a polymer rear and a stainless steel bezel, while its price is already higher than that of the previous generation. For now, Garmin’s nano-molded construction remains associated with its premium titanium watches.

Sources: TechRadar.