C-4 (explosive)
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C-4 or Composition C-4 is a common variety of military plastic explosive.
C-4 is made up of explosive, plastic binder, plasticizer and, nowadays, marker or taggant chemicals such as 2,3-dimethyl-2,3-dinitrobutane (DMDNB) to help detect the explosive and identify its source. As with many plastic explosives, the explosive material in C-4 is RDX (also known as cyclonite or cyclotrimethylene trinitramine) which makes up around 91% of the C-4 by weight. The plasticizer is di(2-ethylhexyl) or dioctyl sebacate (5.3%), and the binder is polyisobutylene (2.1%). Another binder used is dioctyl adipate (DOA). A small amount of SAE 10 non detergent motor oil (1.6%) is also added. C-4 detonates at about 26,400 feet per second (fps). This is about 7,400 fps faster than commercial 60% dynamite.
C-4 is made by combining RDX slurry with binder dissolved in a solvent. The solvent is then distilled away and the mixture is dried and filtered. The final material is an off-white solid which has a similar feel to modelling clay.
The explosive is a 1960s improvement on a British World War II development called Nobel 808 which contained RDX, mineral oil, and lecithin. C-4 is part of a group of explosives along with C, C2 and C3, each containing different amounts of RDX.
The C is sometimes said to stand for composition and the name is an abbreviation of Composition 4. However, the term composition is used for any stable explosive, and "Composition A" and "Composition B" are other known variants. Therefore, C-4 is correctly referred to as Composition C-4.
A major advantage of C-4 is that it can easily be moulded into any desired shape. C-4 can be pressed into gaps/voids in buildings, bridges, equipment or machinery. Similarly, it can easily be inserted into empty shaped-charge cases of the type used by special forces. C-4 is also well known for its durability and reliability. It will not explode even if hit by a bullet, punched, cut, or thrown into a fire. The only reliable method for detonation is via a detonator or blasting cap. However, applying pressure in combination with heat can often cause detonation.
When the military or a demolition company uses C-4 they normally use 8–10 pounds of C-4 to demolish eight inch square steel beams, even though this is more explosive than is required. They do this to make sure that they have accomplished the job successfully.
British plastic explosive is referred to as PE4. Like C-4 it is an off-white coloured solid and its explosive characteristics are nearly identical. The only difference between C-4 and PE4 is the type and proportion of plasticizer used.
A plastic explosive called Semtex is the Eastern European equivalent of C-4.
Trivia
- C-4 was used in the finals of the 1995 "King of the Death match" professional wrestling tournament held in Japan. Death match winner Mick Foley received second degree burns from this explosion.
- Because C-4 burns slowly if a started explosion is not feeding it, during the Vietnam War era, many soldiers would use small amounts of C-4 as means of heating rations while on long patrols. While many soldiers were able to use C-4 in this manner safely, there are several anecdotes about soldiers attempting to put out the fire by stomping on it and causing it to detonate.
- C-4 is a typical explosive used in many movies, TV shows and video games.
- Because C-4 is a modeling-clay like substance, it is especially useful in blowing up doors and safes. Many movies show C-4 being used in this way.
External links
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