Description

Extrema Ratio FAT BOY – Extreme Heavy-Duty Survival Knife (N690)

FAT BOY is the most robust fixed blade knife ever produced by Extrema Ratio. Designed without compromise, this extreme survival and breacher tool features an unprecedented 8.6 mm thick blade made from premium Böhler N690 steel, with a total weight of approximately 1 kilogram.

Inspired by ancient cleavers used as combat and defense tools, FAT BOY is a bold and innovative solution for the most demanding scenarios – from tactical breaching and levering to outdoor chopping, batoning, and survival tasks.

One-of-a-Kind Strength and Durability

FAT BOY is built to endure extreme abuse. Its massive blade thickness, full flat grind and reinforced geometry allow it to function not only as a cutting tool, but also as a striking, levering and prying instrument. It is suitable for:

• Splitting and batoning heavy wood
• Breaching and levering doors, car doors and windows
• Chopping, clearing and digging in emergency situations
• Hammering pegs and stakes using the reinforced spine

Blade Design and Function

The blade features a full flat grind and a specially designed reinforced tip that protects the main cutting edge while allowing controlled penetration and levering. The wide blade profile also enables digging small holes in the ground when required.

The thick, flat blade spine adds mass and provides a durable striking surface, making FAT BOY suitable for hammering and heavy impact use.

Handle Construction

The handle consists of two removable black G10 scales with an original Extrema Ratio design. The scales can be removed for inspection, cleaning or to wrap paracord around the tang, increasing versatility in survival situations.

Sheath and Carry System

Both versions are supplied with a black Cordura sheath featuring an anti-cut rubber blade lock for safe retention. The MOLLE-compatible system is fully ambidextrous and allows:

• Right- or left-handed configuration
• Height adjustment via thigh straps
• Attachment of accessories, pouches or a backup knife
• Replacement of all sheath components individually

Available Blade Finishes

• Satin – classic raw steel appearance
• Dark Stone – reduced reflections, tactical look

Technical Specifications

• Blade material: Böhler N690 stainless steel
• Hardness: 58 HRC
• Blade length: 210 mm
• Total length: 350 mm
• Blade thickness: 8.6 mm
• Weight: 1008 g
• Main grind: Flat
• Handle material: G10
• Blade finish: Satin or Dark Stone

FAQ

Glossary

• Breacher knife: A knife designed for levering, prying and forced entry tasks.
• Full flat grind: A blade grind offering high cutting efficiency and strength.
• G10: A high-strength fiberglass laminate used for durable knife handles.

Manufacturer Information (GPSR)

Extrema Ratio S.R.L.
Via Traversa delle Ripalte 72/74/76/78
59100 Prato (PO)
Italy
Phone: +39 0574 584639
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Website: www.extremaratio.com

Specifications may change without notice as part of continuous product development.