Microtech Dirac Delta D/E OTF Knife Blue Aluminum, Black M390MK by Tony Marfione (227-1BL)

Microtech Dirac Delta D/E Blue Aluminum, Black M390MK by Tony Marfione (227-1BL) – full-size OTF D/A automatic knife

The Microtech Dirac Delta D/E Blue Aluminum, Black M390MK by Tony Marfione (227-1BL) is a full-size OTF automatic knife operating on the D/A system, designed as a larger, more robust version of the Dirac series. The design combines quick blade deployment and retraction with a side-mounted Thumb Slide, making operation intuitive for both right- and left-handed users. The blade, made of Böhler M390MK steel with a D/E Dagger profile, a flat grind, and a Black coating, is designed for effective piercing, stable cutting, and high durability. The handle, made of 6061-T6 aluminum with a blue finish, maintains a slim, ergonomic profile, while the two-position deep-carry clip and a glass breaker with a tungsten carbide ball highlight the practical nature of the Dirac Delta model.

Böhler M390MK – Microtech powder steel for large OTF

Böhler M390MK is a high-performance powder steel developed for Microtech in collaboration with Böhler, designed with a focus on wear resistance, corrosion resistance, and long-lasting sharpness. In the Dirac Delta model, this material performs well when cutting tape, film, cardboard, cord, straps, and technical materials, where stable edge performance and predictable blade guidance are essential. The black finish Black coating enhances the blade’s technical appearance, reduces light reflections, and helps mask minor signs of wear.

D/E Dagger and flat grind – double-sided geometry for precise work

The D/E Dagger profile features a double-edged blade with symmetrical geometry, designed for precise tip control and effective piercing of materials. Long grains on both sides of the blade reinforce the construction and emphasize the technical character of the Dirac Delta series. The flat grind ensures smooth passage of the blade through material, maintaining a favorable balance between cutting edge sharpness and durability. This design fits well with the purpose of a full-size OTF automatic knife, which is intended to combine speed, control, and high mechanical resistance.

6061-T6 Aluminum and D/A OTF – ergonomics, speed, and control

The handle, made of 6061-T6 aluminum, is crafted with high precision, maintaining a slim profile and a curved line inspired by classic Microtech designs. The surface texture and jimping on the spine and underside improve grip stability, even during dynamic use. The distinctive Thumb Slide located in a recess on the Handle allows for natural deployment and retraction of the blade in the D/A OTF system. The two-position deep carry clip allows the knife to be carried in a tip-down position, and the glass breaker with a tungsten carbide ball expands the model’s functionality in emergency situations.

Why choose the Microtech Dirac Delta D/E Blue Aluminum?

The Microtech Dirac Delta D/E Blue Aluminum is designed for users who expect a full-size OTF automatic knife with robust mechanics, refined ergonomics, and high-quality materials. Böhler M390MK steel ensures long-lasting edge performance, the D/E Dagger profile enhances precision during detailed work, and the D/A mechanism allows for quick one-handed deployment and retraction of the blade. The handle, made of 6061-T6 aluminum, combines durability with a comfortable, slim shape, and the right/left tip-down clip allows you to customize how you carry it. This is an OTF automatic knife for those who value speed, precision, and Microtech’s technological aesthetics.

Key features at a glance

• Böhler M390MK — high-performance powder-coated steel.
• D/E Dagger — double-edged blade with symmetrical geometry.
• Flat grind — smooth blade glide through material.
• Black coating — technical, low-reflective blade finish.
• D/A OTF — automatic blade extension and retraction via a slide mechanism.
• Glass breaker — steel component with a tungsten carbide ball.

Technical data

Frequently Asked Questions

How to care for and sharpen the Böhler M390MK steel in the Dirac Delta model?

Böhler M390MK steel should be cleaned and dried after use, especially after contact with moisture, sweat, or debris from cut materials. A diamond sharpener or a high-quality ceramic system works best for sharpening, as powder steel with high wear resistance requires an effective abrasive and a stable angle.

How does the D/A OTF mechanism work in the Microtech Dirac Delta?

The D/A OTF mechanism allows the blade to be extended and retracted by moving the same Thumb Slide. The blade moves back and forth along the handle’s axis, so the knife can be operated with one hand without the need for a traditional side-fold mechanism.

What makes the D/E Dagger profile stand out?

The D/E Dagger is a double-edged blade with symmetrical geometry, designed for precise tip control and effective piercing. The central grain reinforces the blade’s construction and gives it a distinctly technical character.

Why is the slide on the Dirac Delta located on the side of the Handle?

The side-mounted Thumb Slide allows for a more natural hand position when extending and retracting the blade. The recess around the slide helps control the pressure required to operate the mechanism, which increases safety and comfort of use.

Does the Microtech Dirac Delta have a glass breaker?

Yes, the handle features a window breaker with a tungsten carbide ball. This is a structural element of the knife that expands its functionality in emergency situations, but it is not listed as a separate accessory in the technical data.

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