Extrema Ratio BFK N690 Tactical Mud

The Extrema Ratio BFK N690 Tactical Mud is the full-size folder in the BFK series, designed for discreet pocket carry and dependable everyday work. For nearly 30 years, Extrema Ratio has crafted knives for users who demand uncompromising reliability. The BFK follows the same philosophy with precisely machined scales, tight tolerances, and a solid construction that inspires confidence every time the knife is opened or closed.

Crossbar Lock – secure and ambidextrous

At the heart of the BFK is the Crossbar Lock system, securing the blade in the open position with a solid, play-free lockup. The mechanism can be operated with one hand from either side, while keeping the fingers clear of the edge's path when closing.

This allows for fast opening and controlled closing. The lock engages with a solid, reassuring sound, providing a dependable feel with every operation.

Designed for everyday carry

The BFK features a reversible pocket clip, allowing fully ambidextrous carry. The clip keeps the knife discreetly positioned along the edge of the pocket. Weighing just 85.5 g, the BFK remains lightweight and unobtrusive throughout the day while still being ready whenever needed.

Proven N690 blade steel

The blade is made from Böhler N690 stainless steel hardened to 58 HRC. This proven steel combines hardness, resilience, and reliable long-term performance, making it well suited to a knife designed for everyday use.

The 82 mm blade features a flat grind and measures 2.7 mm thick. The Tactical Mud version is finished with a MIL-C-13924 burnished finish, giving the blade its distinctive dark, light-absorbing surface.

Tactical Mud – functional design with a warmer tone

The Tactical Mud version combines a precision-machined anodized Anticorodal aluminum handle with the characteristic burnished blade finish. Its warmer color gives the otherwise highly functional design a distinctive appearance.

The machined scales provide a secure grip and remain dependable in both dry and wet conditions.

Product Features

• Full-size folding knife for EDC and everyday work
• Böhler N690 blade steel, 58 HRC
• 82 mm blade length
• 195.5 mm overall length
• 2.7 mm blade thickness
• Flat grind
• MIL-C-13924 burnished finish
• Crossbar Lock
• One-handed operation
• Ambidextrous lock operation
• Reversible pocket clip for fully ambidextrous carry
• Precisely machined handle scales
• Anodized Anticorodal aluminum handle
• Tactical Mud colorway
• Weight: 85.5 g
• Designed by Extrema Ratio