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Fat Boy is the most robust fixed blade knife ever produced by Extrema Ratio. This is the first model produced in N690 steel (58HRC) with a thickness of 8.6 mm, for a total weight of 1 kg.

Extrema Ratio has committed to the creation of Fat Boy with the usual determination that distinguishes us, combining extreme thickness and design to obtain an unparalleled product, an innovative and bold solution. Its development was inspired by the first cleavers, used as combat and defence weapons since ancient times.

Fat Boy is characterized by an exceptional resistance. It can be defined as a one-of-a-kind striking tool. Thanks to its generous size, Fat Boy is ideal for all heavy jobs, from splitting to disengagement in extreme scenarios, allowing you to carry out different typical breacher activities, including levering to open doors, car doors and windows.

These spectacular features turn into pure fun if we move Fat Boy outdoors, where prepping, chopping and batoning become just formalities.

The blade, characterized by a full flat grind, has a particular tip structure that protects the main cutting edge and combines the ability to penetrate with the possibility of using it as a lever. Its shape and width also allow it to dig small holes in the ground in emergency situations.

The back of the blade, thick and flat at the end, gives this tool a greater mass and a hinged surface, useful for hammering and planting pegs.

The handle is composed of two black G10 scales, featuring a new original Extrema Ratio design. They can be removed and replaced, thus allowing for inspections and checks to be carried out under the handle and for paracord to be wrapped around.

Fat Boy is available in Satin and Dark Stone, both equipped with a black Cordura sheath with an anti-cutting rubber blade lock. The MOLLE system on both sides can be used by both right-handed and left-handed, depending on the side where the two thigh vertical strips for height adjustment are positioned. This system allows you to attach accessories, pouches, or an additional back-up knife, offering the possibility to easily move all the accessories from one side to the other. All sheath components can be individually replaced.

In stock

In stock


Weight g.: 1008
weight oz.: 35.55
Blade Length (mm): 210
Blade Length (in): 83.07
Total Length (mm): 350
Total Length (in): 13.78
Blade Thickness (mm): 8.6
Blade Thickness (in): 0.34
Blade Material: BöHLER N690 STEEL (58HRC)
Blade Finishing: SATIN
Main Grind: FLAT
Handle Material: G10


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