KB Knives Zephyr Flamed Titanium / Wave Carbon Fiber, Silver Beadblasted M390 by K.C. Spiron (KB431B)

KB Knives Zephyr Flamed Titanium / Wave Carbon Fiber Folding Knife, Silver Beadblasted M390 by K.C. Spiron (KB431B)

The KB Knives Zephyr KB431B is a titanium folding knife designed by K.C. Spiron, combining a Böhler M390 steel blade with a handle finished in the Flamed style, featuring fine Micro Milling and a decorative Wave Carbon Fiber inlay. The design features a Liner Lock and ceramic ball bearings, offering smooth operation and a distinctive, refined character.

The 94.00 mm blade features a Drop Point profile, a flat grind, and a silver bead-blasted finish. It opens manually using thumb studs on both sides, and once fully extended, the blade is secured by the Liner Lock.

Böhler M390 and Vacuum-Cryogenic Heat Treatment

The blade is made of Böhler M390 steel, hardened to 60–62 HRC. Vacuum hardening combined with cryogenic treatment was used, which helps achieve high hardness, wear resistance, and stable steel properties during regular use.

Drop Point, flat grind, and Silver Bead Blasted

The Drop Point profile provides a versatile geometry with a well-controlled tip and a functional cutting edge. The flat grind ensures smooth blade glide through the material, while the silver bead-blasted finish gives the blade a matte, subdued appearance.

Flamed Titanium, Micro Milling, and Wave Carbon Fiber

The handle is made of titanium and finished in the decorative Flamed pattern. The surface is complemented by fine Micro Milling and an carbon fiber inlay with a Wave pattern, which enhances the visual contrast of the design. The titanium backspacer and clip feature the same Flamed design.

Ceramic ball bearings ensure smooth blade movement, while the Liner Lock stabilizes the blade when fully open. The clip can be mounted on the right or left side in a tip-up configuration.

Key Features at a Glance

• Böhler M390 — steel with a hardness of 60–62 HRC.
• Vacuum-cryogenic treatment — enhances the steel’s high hardness, wear resistance, and stability.
• Drop Point — a versatile utility profile.
• Flat grind — efficient cutting geometry.
• Silver Bead Blasted — a matte silver finish on the blade.
• Flamed Titanium — a decorative finish on the titanium handle.
• Micro Milling — fine milling of the handle surface.
• Wave Carbon Fiber — decorative carbon fiber inlay.
• Liner Lock — a lock that stabilizes the blade when open.
• Ceramic ball bearings — smooth operation of the mechanism.
• Thumb studs on both sides — manual opening.

Technical data

Frequently Asked Questions

How do I care for Böhler M390 steel?

It’s a good idea to clean the blade regularly and dry it thoroughly. M390 has high corrosion resistance, but proper care helps maintain sharpness and the surface’s appearance for longer.

How do I sharpen the KB Zephyr?

High-performance abrasives, especially diamond-coated ones, work well with M390 steel. It’s best to maintain the factory edge geometry and guide the sharpener evenly along the entire length of the blade.

How does the Liner Lock work?

The Liner Lock utilizes a spring-loaded liner component that, when the knife is opened, moves behind the blade and stabilizes the blade in the open position.

How do you care for the Wave Carbon Fiber inlay?

It’s best to use a soft, slightly damp cloth for cleaning. Avoid harsh chemicals and abrasive materials, which can alter the appearance of the inlay’s surface.

How to maintain ceramic ball bearings?

It’s a good idea to regularly clean the area around the pivot of dust and fine debris. If necessary, you can use a small amount of a cleaner designed for knife mechanisms.

Prepared by: Specialists at Sharg® company – Your expert in EDC and cutting tools