Thursday, April 4, 2013



It is a chemically unstable material which is when suitably initiated, change its chemical composition rearranging its molecules to become stable from an unstable structure, resulting intense pressure on its surrounding with a simultaneous evolution of great amount of heat and gases causing destruction.


Low explosive

An explosive whose velocity of detonation is less than 331 m/s (Speed of Sound) is called low explosive. When initiated, chemical reaction is comparatively slow. Low explosive are mostly solid combustible materials that decomposed rapidly, but do not normally explode. This action is known as deflationary  Black powder, smoke powder, Gun powder and carbide are example of low explosive.

ii. High Explosive
An explosive whose velocity of detonation is more than 331 m/s (Speed of Sound) is called High explosive. . When initiated, chemical reaction is very fast. When initiated by a blow or shock, it decomposes almost instantaneously
TNT (Tri Nitro Toluene) RDX, (Research Departmental Explosive), C-4 (Composition-4), PETN (Penta  Erythritol Tetra Nitrate), NG (Nitro Glycerin), ANFO (Ammonium Nitro Fuel Oil), TATP (Tri Acetone Tri Per Oxide) SEMTEX (Plastic Explosive) High Explosive Further Divided into two Groups.

a. Primary High Explosive.

A Primary High Explosive is an explosive that is extremely to stimuli such as impact. Friction, heat static electricity or electromagnetic radiation. A relatively small amount of energy is required for initiation . e.g Lead Azide, Led Styphnate , Silver Azide, Mercury Fulminate, Mercury Nitride, Nitro Glycerin ,PETN. 

b. Secondary High Explosive 
A secondary High Explosive is less sensitive than a primary explosive and require substantially more energy to be initiated. Because they are less sensitive are usable in a wider variety of applications and are safer to handle and store. Secondary Explosive are used in larger quantities in an explosive train and are usually initiated by a smaller quantity of primary explosive. e.g TNT,RDX,C-4,SEMTEX.

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