Composition B

2025-06-06T15:00:34Z

2A06:5904:3C0E:6500:D5D:F29B:14A6:45A6:

{{Short description|Explosive, a mix of RDX and TNT}}
[[File:DM41 hand grenade cutaway.png|thumb|300px|Post-World War II German [[M26 grenade#DM41_(West_Germany)|DM41 fragmentation hand grenade]] filled with Composition B. This example has been dissected to reveal the steel fragmentation sleeve and yellow explosive charge.]]

'''Composition B''' ('''Comp B'''), also known as '''Hexotol''' and '''Hexolite''' (among others), is a high [[explosive]] consisting of castable mixtures of [[RDX]] and [[Trinitrotoluene|TNT]]. It is used as the main explosive filling in [[artillery]] [[shell (projectile)|projectile]]s, [[rocket]]s, [[land mine]]s, [[hand grenades]], and various other [[munitions]].<ref name="Cooper - Explosives Engineering">{{cite book|last=Cooper|first=Paul W.|title=Explosives Engineering|year=1996|publisher=Wiley-VCH|isbn=978-0-471-18636-6}}</ref> It was also used for the [[explosive lens|explosive lenses]] in the first implosion-type [[nuclear weapon]]s developed by the United Kingdom and United States.<ref name="Coster-Mullen">''Atom Bombs: The Top Secret Inside Story of Little Boy and Fat Man'', John Coster-Mullen, 2003</ref><ref name="NWFAQ">[http://www.nuclearweaponarchive.org/Nwfaq/Nfaq8.html#nfaq8.1.1 Nuclear Weapons FAQ section 8.1.1: The Design of Gadget, Fat Man, and "Joe 1" (RDS-1)], accessed August 10, 2009</ref>

The standard proportions of ingredients (by weight) are 59.5% RDX ([[detonation velocity]] of 8,750 m/s) and 39.5% TNT (detonation velocity of 6,900 m/s), [[phlegmatized]] with 1% [[paraffin wax]].<ref>Military Specification MIL-C-401</ref> Most commonly it is described as 60/40 RDX/TNT with 1% wax added.

== Properties ==
* Density: 1.65 g/cm<sup>3</sup>
* Velocity of [[detonation]]: 8,050 m/s

== Use ==
Composition B was extremely common in [[Western World|Western nations']] munitions and was the standard explosive filler from early [[World War II]] until the early 1950s, when less sensitive explosives such as [[Composition H6]] began to replace it in many weapons.{{Citation needed|date=August 2009}} M65 bombs from 1953 containing degraded Composition B were responsible for much of the damage in the 1967 [[USS Forrestal fire|USS ''Forrestal'' fire]].

Some [[NATO]]-approved munitions suppliers such as [[Mecar]] have continued to use Composition B in their products.

Composition B is related to [[Cyclotol]], which has a higher proportion of RDX (up to 75%).

[[IMX-101]] is slowly replacing Comp B in US military artillery shells, and IMX-104 <ref>{{Cite journal|last=Walsh|first=Michael R.|last2=Walsh|first2=Marianne E.|last3=Ramsey|first3=Charles A.|last4=Thiboutot|first4=Sonia|last5=Ampleman|first5=Guy|last6=Diaz|first6=Emmanuela|last7=Zufelt|first7=Jon E.|date=2014-04-01|title=Energetic Residues from the Detonation of IMX-104 Insensitive Munitions|journal=Propellants, Explosives, Pyrotechnics|language=en|volume=39|issue=2|pages=243–250|doi=10.1002/prep.201300095|issn=1521-4087}}</ref> in mortar rounds and hand grenades.

== Gallery ==
<gallery widths="150" heights="200">
File:DM41 3.jpg|German [[M26 grenade|DM41 fragmentation hand grenade]] labelled to indicate a filling of Composition B.
File:USMC-100414-M-5241M-001.jpg|[[M107 projectile|M107 projectiles]]. All are labelled to indicate a filling of "Comp B" and have [[Fuze|fuzes]] fitted.
File:US Army Military Engineers working with explosive device - Exercise Talisman Sabre 2011.jpg|A {{Convert|40|lb|kg|0|abbr=on}} [[shaped charge]] munition (marked to indicate a Composition B filling) used for various demolition purposes such as boring a hole for a cratering charge.
File:Ford_MUTT_M151A1C_FSN_2320-763-1091_pic1.JPG|The 106mm recoilless rifle [[High-explosive anti-tank|HEAT]] shell on the right is marked "Comp B".
</gallery>

== See also ==
* [[Composition C]]
* [[Cyclotol]]
* [[RE factor]]
* [[Semtex]]

== References ==
{{reflist}}

[[Category:Explosives]]
[[Category:Trinitrotoluene]]

Vero - Wikipedia - User contributions [en]

Composition B