Secondary Explosive
Definition
A high explosive insensitive to normal friction, spark, and percussion; requires a primary explosive shock or blasting cap to initiate detonation. Examples: TNT, RDX, PETN, HMX, ANFO. Forms the main charge in military and commercial applications.
- Sensitivity
- Insensitive to normal friction, spark, and percussion. Requires a primary shock or blasting cap to detonate.
- Common types
- TNT, RDX, PETN, HMX, nitroglycerin, ANFO
- Primary role
- Forms the main charge in military and commercial blasting applications
Common questions
What makes a secondary explosive different from a primary explosive?+
A secondary explosive is relatively insensitive to friction, sparks, and impacts on its own. Unlike a primary explosive, it requires a strong shock or blasting cap from a primary explosive to detonate. This makes it safer to handle and store for most applications.
What are common examples of secondary explosives?+
TNT, RDX, PETN, HMX, and ANFO (ammonium nitrate/fuel oil) are all secondary explosives. These are the dominant class in military and commercial blasting operations because they are powerful yet require a deliberate initiating shock to detonate.
Why are secondary explosives used as the main charge in bombs or blasting operations?+
Secondary explosives form the bulk of the charge because they deliver high power and can be handled relatively safely without accidental detonation. A small primary explosive initiates the secondary, which then releases the main destructive force. This two-stage approach gives precise control over when and how the explosion occurs.
Related terms
- Brisance
- The shattering power of a detonating explosive, distinct from heave (bulk displacement). Measured by the Trauzl lead block test. High-brisance explosives (RDX,...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...
- Primary Explosive
- A high explosive sensitive enough to detonate from friction, spark, percussion, or flame without confinement or a separate booster. Examples: mercury fulminate,...
- ANFO
- Ammonium nitrate fuel oil: 94% ammonium nitrate prills + 6% diesel fuel oil. Detonation velocity approximately 4,500-4,800 m/s. The most widely used...
- Chapman-Jouguet Velocity
- The minimum stable detonation velocity for a given explosive at a specific density, a thermodynamic property of the explosive composition. Used to...
- Deflagration-to-Detonation Transition (DDT)
- The acceleration of a deflagrating burn front to supersonic detonation velocity, triggered by confinement. Relevant to understanding how improvised devices using low...
- Ion Chromatography (IC)
- An analytical technique that separates and quantifies anions and cations in solution. In post-blast residue analysis, IC detects nitrate, nitrite, ammonium, and...
- Oxygen Balance
- A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2...
- PESO (India)
- Petroleum and Explosives Safety Organisation, the Indian government body under the Ministry of Commerce and Industry that administers the Explosives Act 1884...
- Smokeless Propellant
- A low explosive based on nitrocellulose (single-base), nitrocellulose plus nitroglycerin (double-base), or nitrocellulose plus nitroglycerin plus nitroguanidine (triple-base). Used as firearm propellant...
- Tertiary Explosive (Blasting Agent)
- An ammonium nitrate-based explosive formulation requiring both a primary and a booster charge for reliable initiation. ANFO is the globally dominant blasting...
Explained in these topics
- Explosives Classification: Low vs High, Primary vs SecondaryA high explosive insensitive to normal friction, spark, and percussion; requires a primary explosive shock or blasting cap to initiate detonation. Examples: TN...
- Explosives Classification: Low, High, Primary, Secondary, TertiaryA relatively insensitive high explosive that requires initiation by a primary explosive shock. Examples: TNT, RDX, PETN, HMX, nitroglycerin. The dominant class...