COMMON NAME – Composition B
FOREIGN NAMES – Cyclotol (US), Hexolite (France), Füllpulver Nr. 18 & Füllpulver Nr. 95 (Germany), Tritolite (Italy), Trilota (Spain), Bonit or Hexotol (Sweden), Chauyaku or Nigotanoyaku Mk 2(Japan)
TYPE – High explosive mixture
DATE FIRST USED AS AN EXPLOSIVE – 1935
COUNTRY OF ORIGIN – Great Britain & Germany
COMPOSITION – 59.5% RDX, 39.5% TNT, 1% Desensitizer (Paraffin Wax) (US Comp B)
MOLECULAR FORMULA – C3H6N6O2 (RDX) + C7H5N3O6 (TNT) + CH3 (CH2)11CH3 (Wax)
MOLECULAR WEIGHT – 224
DENSITY – 1.68 g per ml
NORMAL STATE – Solid
PHYSICAL APPEARANCE/COLOR – Dirty white to brownish yellow
INITIATION – Minimum detonating charge 0.22 g Mercury fulminate, 0.20 g Lead azide
SENSITIVITY – Insensitive to friction, less sensitive to shock than TNT, detonates 20% of the time from a 7.62mm (.30 cal) bullet impact
STABILITY – Stable in storage
DETONATION VELOCITY – 7,840 m/s (25,722 fps)
RE FACTOR (BRISANCE) [TNT=1.0] – 1.35
TOXICITY – Same as for TNT and RDX
MELTING POINT – 79o C. (174o F.) melts to slurry
IGNITION POINT – 188o to 270o C.(370o to 518o F.) Detonates
SOLUBILITY – Relatively insoluble in water (RDX & TNT components)
APPLICATIONS – PRINCIPLE USES – Explosive filler for all types of non-armor piercing ordnance
Composition B is the code name for the mixture of two high explosives, RDX and TNT including a small portion of desensitizing materials, usually wax. The RDX/TNT mixtures are designated Cyclotols with the additional specification of their explosive mix ratio. Composition B is the specific mixture of 60% RDX, 39% TNT, and 1 % wax, also known as 60/40 Cyclotol. The explosive mixtures were developed in Great Britain between World War I and II, to make use of the power of RDX, combined with the stability of TNT. The explosive can be melted and cast into artillery shells and other ordnance that does not have to penetrate a hard target. It has been extensively used as the explosive filler in bombs, shells, mines, and grenades. Composition B was also the “fast-burning” component of the explosive lenses used in the Fat Man atomic bomb design.
