Microtech Dirac Delta D/E OTF Knife Weathered Blue Aluminum, Weathered Blue M390 by Tony Marfione (227-1WBL)

Dirac Delta D/E Weathered Blue Aluminum, Weathered Blue is a larger OTF automatic knife from the Dirac series. It operates in D/A mode and features an incredibly fast blade-ejection mechanism. The slide button is located on the side of the handle. 100% manufactured and assembled in the USA. Designed by Anthony Marfione, a knife maker and owner of Microtech Knives.

Dirac Delta® is an enlarged version of the first OTF D/A (Double Action) automatic knife in the Microtech® lineup, equipped with a slider located in a recess on the side of the handle. This model features a modern, ergonomic handle with curved lines inspired by the iconic HALO® model. The Dirac Delta® series incorporates Microtech®’s signature premium features—patented screws, an innovative internal mechanism, and a functional glass breaker. With a total length of 9.25 inches, the Dirac Delta® is an excellent choice as an everyday carry (EDC) knife.

M390 - a high-performance martensitic chromium steel produced using powder metallurgy. Due to its alloy composition, it features exceptionally high wear resistance and high corrosion resistance. Thanks to its high wear resistance, it retains its edge shape well, allowing the blade to stay sharp for a very long time (requires minimal maintenance). Another advantage is its resistance to “wire” formation during sharpening. Steel with a high chromium content of 20.0% (Cr), alloyed with 1.9% carbon (C) and 4.0% vanadium (V), hardened to a range of 59–61 HRC. This super steel is comparable to Carpenter’s CPM 20CV or CTS-204P steels. Manufactured by Böhler Edelstahl in Kapfenberg, Austria.

Blade - machine-ground D/E (Double Edge) Dagger style, double-edged with a long line of reinforcing grooves on both sides of the blade for strength. Finished with a blue, rubbed-in Weathered Blue coating. The blade features a high flat grind, ensuring excellent cutting performance. This allows the knife to maintain high strength while offering outstanding piercing capabilities. The centrally located fuller further reinforces the blade. The robust blade extension/retraction mechanism, operated by a knurled Thumb Slide, a stepped thumb slide, requires a specific amount of force to overcome spring resistance for safety. This opening mechanism ensures smooth operation for both right- and left-handed users.

Handle - precision-machined using 3D technology on CNC mills, made of 6061-T6 aluminum with a Weathered Blue finish. The textured surface of the handle prevents the knife from slipping in the hand during use. There are notches (jimping) on the back and bottom of the handle for a more secure grip. A distinctive feature is the placement of the slider in a recess milled into the side of the handle. This allows the hand to rest more naturally when opening and closing the knife. The slim profile and the milled, two-position (right/left) solid deep carry clip allow for discreet carrying of the knife in a pocket in the tip-down position (blade tip pointing down). The clip features the Microtech logo, serial number, and date of manufacture. The handle is finished with a glass breaker, a solid steel triangle into which a tungsten carbide ball has been pressed.

Technical Specifications:

Product Number: 227-1 WBL
Product name: Dirac Delta® D/E Weathered Blue Aluminum, Weathered Blue Standard

Overall length: 235.0 mm / 9.25“
Blade length: 95.2 mm / 3.75”
Blade thickness: 3.0 mm / 0.12"
Handle length: 140.0 mm / 5.5“
Handle thickness: 12.7 mm / 0.5”
Weight: 129.0 g / 4.55 oz

Blade material: Böhler M390
Blade hardness: N/A
Blade grind: Flat
Blade finish: Weathered Blue

Handle material: 6061-T6 Aluminum
Handle finish color: Weathered Blue
Backspacer material: 6061-T6 Aluminum
Backspacer color: Weathered Blue

Clip: Right / Left, Tip-down
Clip material: Stainless Steel

Pivot mechanism: N/A
Lock: Slide Lock
Opening method: Automatic, push/pull thumb slider
Additional accessories: None

Designer: Anthony Marfione
Brand: Microtech
Manufacturer: Microtech Knives
Country of origin: USA

Prepared by: Sharg®