Okfol

OKFOL (Ockfol) — a high-velocity, high-brisance phlegmatized explosive. It consists of desensitized HMX (High Melting Explosive). It typically appears as a fine crystalline powder or pressed charges, colored white, yellowish, or pink (depending on the specific grade and phlegmatizer dye).

Composition

Military standards for Okfol feature several modifications (e.g., Okfol-5, Okfol-9), but the classic baseline composition is as follows:

• HMX (Octogen): — 95% (main explosive filler)

• Phlegmatizer (Oksizin, or wax/plasticizer with dye): — 5% (added to reduce sensitivity to mechanical impact).

Physicochemical Properties

• Melting Point: The base component, HMX, melts at a very high temperature (approximately 276–280°C / 528–536°F) while simultaneously decomposing. Okfol itself lacks a distinct low melting point, meaning it cannot be melt-poured into munitions in its pure form; charges are manufactured primarily via pressing.

• Solubility: Insoluble in water, poorly soluble in alcohols. Readily soluble in dimethylformamide (DMF) and acetone.

• Hygroscopicity: Practically non-hygroscopic; it does not absorb atmospheric moisture and retains its explosive properties even during prolonged storage in damp environments.

Explosive Characteristics

• Detonation Velocity: ~8,400–8,700 m/s (depending on loading/pressing density).

• Relative Effectiveness Factor (RE-factor): ~1.5–1.7 (significantly more powerful than TNT and RDX).

• Sensitivity: Due to the 5% phlegmatizer content, its sensitivity to impact and friction is substantially reduced compared to pure HMX, making it safer for industrial manufacturing and munition filling. However, it remains more sensitive than pure TNT.

Toxicity and Safety

Highly toxic substance. Inhalation or ingestion of Okfol dust causes systemic poisoning, leading to central nervous system damage and severe impairment of internal organs (liver and kidneys). The use of personal protective equipment (PPE), including respirators and skin protection, is mandatory when handling the material.

Applications

Due to its exceptionally high detonation velocity and detonation pressure, Okfol is widely utilized as a primary explosive filler for high-efficiency shaped charges. It is commonly found in:

• Warheads of anti-tank guided missiles (ATGMs).

• Shaped charges for rocket-propelled grenades (RPGs).

• Submunitions for cluster artillery shells and rockets.

• Specialized demolition charges (linear and focal shaped charges) requiring maximum armor-piercing capability.

Special Notes / Safety Warnings

Pressed Okfol charges are highly dense but brittle. Avoid heavy mechanical stress or direct impacts on unprotected pressed blocks. If ignited in bulk quantities or inside confined spaces, Okfol is highly prone to a rapid deflagration-to-detonation transition (DDT).