Microtech Dirac Delta D/E Signature OTF Knife 250th Anniversary 4th of July Aluminium, Apocalyptic M390MK by Tony Marfione (227-10APS-4J250)

Microtech Dirac Delta D/E Signature 250th Anniversary 4th of July, Apocalyptic M390MK by Tony Marfione – large OTF automatic knife

The Microtech Dirac Delta D/E Signature 250th Anniversary 4th of July Aluminum OTF automatic knife, Apocalyptic M390MK by Tony Marfione (227-10APS-4J250) is a larger, more substantial version of the Dirac, produced as part of the Signature Series anniversary edition to commemorate the 250th anniversary of U.S. independence. The model features a double-edged Dagger blade made of Böhler M390MK steel with an Apocalyptic finish and an aluminum handle decorated with the years 1776–2026.

With a blade length of 96.27 mm and a weight of 130.41 g, it is noticeably larger than the standard Dirac. A central slide mechanism allows for automatic blade extension and retraction, and the symmetrical design supports both right- and left-handed use. The glass breaker features an integrated lanyard hole, and serial numbers may vary by individual unit.

Böhler M390MK – Durability on Both Edges

The blade is made of Böhler M390MK stainless steel, which ensures high corrosion resistance and good durability of both smooth cutting edges. The material meets the requirements of a large, precision-engineered OTF automatic mechanism.

D/E Dagger and Apocalyptic Finish

The Dagger profile features a symmetrical shape, a centrally positioned tip, and two smooth Plain edges. The flat grind supports the blade’s uniform geometry, while the Apocalyptic finish gives the surface a rugged, factory-aged look.

Dirac Delta – Center-Mounted Slider in a Larger Format

The Dirac Delta retains the center-mounted slider characteristic of the Dirac line, but offers a larger handle, a longer blade, and greater weight. The 6061-T6 aluminum frame, featuring the 250th Anniversary 4th of July, 1776–2026 motif, gives the model a commemorative and collectible character.

Key Features at a Glance

• Böhler M390MK — stainless steel ensuring the durability of both edges.
• D/E Dagger — symmetrical, double-edged blade.
• Flat — a flat grind with uniform geometry.
• Apocalyptic — a finish that minimizes the visibility of marks.
• Double Action OTF — automatic opening and closing of the blade.
• Center Slider — ambidextrous mechanism design.
• 250th Anniversary — commemorative edition 1776–2026.
• Dirac Delta — a larger and heavier variant of the Dirac platform.

Technical Data

Frequently Asked Questions

How do I care for Böhler M390MK steel?

After use, clean the blade and dry it thoroughly on both sides. Despite its high corrosion resistance, do not allow moisture, salt, or aggressive contaminants to remain on it.

How do I sharpen the D/E blade on the Dirac Delta?

Both edges should be sharpened separately, maintaining the same angle and symmetry relative to the blade’s axis. Due to its larger size, it’s best to use a guided sharpening system that ensures the knife remains stable.

How does the central slide work?

Sliding the mechanism forward extends the blade, and sliding it backward automatically retracts the blade. Its central position makes it easy to use the mechanism with either your right or left hand.

How do you clean the Dirac Delta mechanism?

You should regularly remove dust, lint, and dirt from the blade opening and the slider guide. Only a small amount of a suitable cleaning agent is needed for maintenance, as excess can attract dust.

What is the difference between the Dirac and the Dirac Delta?

The Dirac Delta has a longer blade, greater overall length, and is nearly twice as heavy. The standard Dirac is more compact, while the Delta offers a larger handle and a more substantial design while retaining a similar mechanism.

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