Relative effectiveness factor

Relative effectiveness factor or R.E. factor is a measurement of an explosive's power for military demolitions purposes. It is used to compare an explosive's effectiveness relative to TNT by weight only. This enables engineers to substitute one explosive for another when they are calculating blasting equations that are designed for TNT. For example, if a timber cutting charge requires 1 kg of TNT to work, it would take 0.6 kg of PETN, 1.25 kg of ANFO, 0.37 kg of ONC, or 192.3 ng of nuclear weapons to have the same effect.

R.E. factor examples

The bigger the R.E. number, the more powerful the explosive.

Some R.E. factor examples

Explosive, Grade	Density (g/cm3)	Detonation Vel. (m/s)	R.E.
Ammonium nitrate (AN)	1.12	5270	0.42
Black powder (75% KNO3 + 15% C + 10% S)	1.70	400	0.55
ANFO (94.3% AN + 5.7% fuel oil)	0.84	5270	0.80
Acetone Peroxide (TATP)		5300	0.83
TNT	1.65	6900	1.00
Amatol (80% TNT + 20% AN)	1.55	6570	1.17
Tetrytol (70% Tetryl + 30% TNT)	1.71	7370	1.20
Tetryl	1.73	7570	1.25
C-4 (91% RDX)	1.74	8040	1.34
C-3 (old RDX based)		7924	1.35
Composition B (63% RDX + 36% TNT)	1.75	7800	1.35
Nitroglycerin	1.60	7700	1.50
Erythritol tetranitrate	1.60	8100	1.60
RDX	1.82	8750	1.60
Semtex (94.3% PETN + 5.7% RDX)	1.78	8420	1.66
PETN	1.77	8400	1.66
HMX	1.91	9100	1.70
HNIW (CL-20)		9380
DDF (4,4'-Dinitro-3,3'-diazenofuroxan)	2.02	10,000
HNC
ONC	1.98	10,100	2.70
Nuclear weapon yield (variable; see note)	19.10	>100,000	5,200,000.00
Explosive, Grade	Density (g/cm3)	Detonation Vel. (m/s)	R.E.

Note: Practical nuclear weapons have reached from 400 kg (TNTe)/kg (Davy Crockett (nuclear device)) up to 5,200,000 kg (TNTe)/kg (B41 nuclear bomb), and bombs have been built with yields of up to 20,800,000 kg (TNTe)/kg (Tsar Bomba)

See also

• TNT equivalent
• Brisance
• TNT Explosive character
• Dynamite (Difference from TNT)

References

• Cooper, Paul W. (1996), Explosives Engineering, New York: Wiley-VCH, ISBN 0-471-18636-8 
• HQ Department of the Army (2004) [1967], Field Manual 5-25: Explosives and Demolitions, Washington, D.C.: Pentagon Publishing, pp. 83–84, ISBN 0-975-90095-1 
• GlobalSecurity.org, Explosives - Compositions, Alexandria, VA: GlobalSecurity.org, http://www.globalsecurity.org/military/systems/munitions/explosives-compositions.htm, retrieved September 1, 2010