FKM Rubber: Built to Last

With applications in the aerospace, automotive, oil and gas industries and more, there are few materials more prevalent than fluroelastomer (FKM) rubber. In the watch industry, it's the go-to for high end rubber straps from brands like Rubber-B, Everest, Vagenari, and more due to its resilience, flexibility, and sleek appearance. From professional divers to office workers, FKM straps offer the perfect balance of form and function - comfortable yet durable.

Origins

Developed in the late 1950's by DuPont, FKM is a type of synthetic rubber made to withstand extreme conditions, making it perfect for industrial applications thanks to its exceptional heat, chemical, and oil resistance.

Over time, it has found its way from aircraft engines and automotive seals to luxury accessories, where its versatility has made it a crowd favourite for watch straps.

Why Makes FKM Stand Out

Unlike silicone or natural rubber, FKM rubber is composed of fluorinated hydrocarbons, a unique chemical structure that gives it outstanding resistance to heat, oils, UV radiation, and oxidation, ensuring that FKM retains its flexibility and structure under stress, making it one of the most stable elastomers available.

What sets it apart:

Temperature Resistance: FKM can endure a wide range of temperatures from –20°C to over 200°C without cracking or hardening.
Chemical Resistance: Unaffected by oils, fuels, sweat, and most solvents, FKM is perfect for daily wear.
UV Resistance: Outdoor wear is not an issue for FKM rubber, allowing it to maintain its colour even under prolonged exposure to sunlight.
Non-porous surface: Its dense structure resists dirt and moisture, keeping it fresh even with daily wear.

The Crafting Process

It begins with raw FKM polymer, which is then blended with curing agents and stabilizers before being vulcanized, a controlled heating process that gives the material its signature strength and elasticity.

Once cured, the rubber is compression or injection moulded into the strap's shape. Each piece is inspected to ensure consistent thickness and flexibility, especially around the lugs and buckle holes where stress is highest.

Finally, finishing touches such as the texture, surface finish, and deboss/emboss branding are added. Some FKM straps are also paired with metal hardware (think Rolex Oysterflex).

Look and Feel

Unlike silicone which can attract dust/lint and become sticky over time, FKM has a smooth, dense, and premium texture. Of course, the surface finishing will be highly dependent on the design of the strap as it can be smooth or textured.

It also maintains a rich, uniform matte finish that pairs beautifully with modern sports watches and divers. No matter the colour, FKM rubber looks refined, a far cry from the plasticky feel of lower-grade rubbers.

Thanks to its resistance to fading and deformation, FKM retains its original colour and structure for years even with daily exposure to sunlight or saltwater.

Why Choose FKM Rubber?

FKM rubber has become a staple in the watch space for several good reasons:

Performance in all conditions: From the ocean to the office, FKM handles it all. Its resistane to saltwater, swear, and UV radiation ensures it never breaks down or discolours, even after years of wear.
All-day Comfort: The material's inherent flexibility and smooth texture make it exceptionally comfortable, especially during heat or activity when leather or metal might feel restrictive.
Low Maintenance: A quick rinse with water and mild soap keeps it clean. FKM doesn't absorb sweat or oils, making it ideal for humid climates or active users.
Aesthetic Versatility: FKM rubber complements nearly any timepiece from dive watches to dress watches - Cartier Tanks on rubber straps seem to be trending these days. Its clean, modern lines lend a contemporary edge to steel or precious metal cases.
Longevity: Unlike silicone straps that crack or tear with age, FKM can last many years with minimal care.

FKM straps offered at Nomad Watch Works

Here at Nomad Watch Works, our FKM rubber straps come in a wide range of designs, colours, and buckle options to suit every watch and wrist. Each strap is crafted from premium-grade fluoroelastomer, offering exceptional comfort, flexibility, and resistance to wear.

For those seeking something more distinctive, we also offer custom FKM rubber straps with a sailcloth pattern, combining the ruggedness of rubber with the refined texture of woven fabric.

Below are some of the FKM straps available from our collection, each built to deliver durability, versatility, and timeless style.

Cut-to-size (CTS) FKM Straps

My personal favourite, you might spot me wearing one on my Omega Seamaster Midsize 2552.80 or Seiko SARB035. Available in sizes from 18mm to 22mm and 4 distinct designs, there’s a CTS strap here for every watch and wrist.

Performax Sailcloth Nylon Hybrid Strap

For those who prefer something a little different, our Performax Sailcloth Nylon Strap offers the best of both worlds - a rubber strap that looks like nylon, giving you the durability and water resistance of FKM with the look and feel of sailcloth nylon.

Foldfit FKM Rubber Strap

Drawing inspiration from Omega’s renowned foldover clasp, the FoldFit FKM strap is our refined take on a classic design, engineered for comfort and durability.

Custom Sailcloth FKM

For those looking for a custom strap done, we offer custom FKM rubber straps with a sailcloth pattern, allowing you to tailor the strap to your liking while retaining the same robust qualities that FKM offers.

Care & Maintenance

As someone who wears a FKM strap daily, be it for work, exercise, or just heading out with friends, here's how I take care of my straps. Give it a wash with mild soap occasionally as dirt, sweat, and dead skin and accumulate after some time. I also give it a rinse after every run. Store it flat or curved naturally as sharp bends crease the rubber and damage it over time.

With minimal care, an FKM rubber strap can last many years while looking new.

Final Thoughts

For watch enthusiasts who demand reliability without sacrificing aesthetics, FKM offers the perfect balance. It’s durable enough for the most rugged adventures yet sleek enough for the boardroom. Unlike traditional rubber or silicone, FKM feels genuinely premium: engineered to complement your timepiece, not just hold it in place.

Whether you’re diving into the sea, training outdoors, or heading to a meeting, a well-crafted FKM strap from Nomad Watch Works ensures your watch looks sharp and feels comfortable every time you wear it.