It is stable in storage and is considered one of the most energetic and brisant of the military high explosives,[2] with a relative effectiveness factor of 1.60.

[6] In the 1930s, the Royal Arsenal, Woolwich, started investigating cyclonite to use against German U-boats that were being built with thicker hulls.

[8] The first public reference in the United Kingdom to the name RDX, or R.D.X., to use the official title, appeared in 1948; its authors were the managing chemist, ROF Bridgwater, the chemical research and development department, Woolwich, and the director of Royal Ordnance Factories, Explosives.

[9] RDX was widely used during World War II, often in explosive mixtures with TNT such as Torpex, Composition B, Cyclotols, and H6.

[20] The demolition of the Jamestown Bridge in the U.S. state of Rhode Island was one instance where RDX shaped charges were used to remove the span.

In laboratory settings (industrial routes are described below separately) it is obtained by treating hexamine with white fuming nitric acid.

[24] RDX had the major advantages of possessing greater explosive force than TNT and required no additional raw materials for its manufacture.

Thus, it was also extensively used in World War I[24] RDX was reported in 1898 by Georg Friedrich Henning (1863-1945), who obtained a German patent[25] for its manufacture by nitrolysis of hexamine (hexamethylenetetramine) with concentrated nitric acid.

[26] During WWI, Heinrich Brunswig (1865-1946) at the private military-industrial laboratory Zentralstelle für wissenschaftlich-technische Untersuchungen [de] (Center for Scientific-Technical Research) in Neubabelsberg studied the compound more closely and in June 1916 filed two patent applications, one for its use in smokeless propellants[27] and another for its use as an explosive, noting its excellent characteristics.

[28][29] The German military hadn't considered its adoption during the war due to the expense of production[30] but started investigating its use in 1920, referring to it as hexogen.

[9] The hexamine-nitration and RDX purification plants were duplicated (i.e. twin-unit) to provide some insurance against loss of production due to fire, explosion, or air attack.

[44] By 1942 the Royal Air Force's annual requirement was forecast to be 52,000 long tons (53,000 t) of RDX, much of which came from North America (Canada and the US).

[46] Gilman states that the same method of production had been independently discovered by Ebele in Germany prior to Schiessler and Ross, but that this was not known by the Allies.

[47] In contrast, the National Defense Research Committee (NDRC), who had visited The Royal Arsenal, Woolwich, thought new explosives were necessary.

[44] In 1941, the UK's Tizard Mission visited the US Army and Navy departments and part of the information handed over included details of the "Woolwich" method of manufacture of RDX and its stabilisation by mixing it with beeswax.

[44] Given the immediate need for RDX, the US Army Ordnance, at Blandy's request, built a plant that copied the equipment and process used at Woolwich.

[49] The Woolwich or direct nitration process has at least two serious disadvantages: (1) it used large amounts of nitric acid and (2) at least one-half of the formaldehyde is lost.

[50] At least three laboratories with no previous explosive experience were instructed to develop better production methods for RDX; they were based at Cornell, Michigan, and Pennsylvania State universities.

[50] The expanded production of RDX could not continue to rely on the use of natural beeswax to desensitize the explosive as in the original British composition (RDX/BWK-91/9).

[52] At the end of 1944, the Holston plant and the Wabash River Ordnance Works, which used the Woolwich process, were producing 25,000 short tons (23,000 t) (50 million pounds) of Composition B per month.

In the original Woolwich process, RDX was phlegmatized with beeswax, but later paraffin wax was used, based on the work carried out at Bruceton.

In the event the UK was unable to obtain sufficient RDX to meet its needs, some of the shortfall was met by substituting amatol, a mixture of ammonium nitrate and TNT.

[55] Considerable quantities of the RDX–TNT mixture were produced at the Holston Ordnance Works, with Tennessee Eastman developing an automated mixing and cooling process based around the use of stainless steel conveyor belts.

[67][68] In July 2012, the Kenyan government arrested two Iranian nationals and charged them with illegal possession of 15 kilograms (33 pounds) of RDX.

[71] Two letter bombs sent to journalists in Ecuador were disguised as USB flash drives which contained RDX that would detonate when plugged in.

[79] RDX has caused convulsions (seizures) in military field personnel ingesting it, and in munition workers inhaling its dust during manufacture.

The symptom complex involved nausea, vomiting, generalized seizures, and prolonged postictal confusion and amnesia; which indicated toxic encephalopathy.

[80] A case has been reported of a human child hospitalized in status epilepticus following the ingestion of 84.82 mg/kg dose of RDX (or 1.23 g for the patient's body weight of 14.5 kg) in the "plastic explosive" form.

[88] It is known to be a kidney toxin in humans and highly toxic to earthworms and plants, thus army testing ranges where RDX was used heavily may need to undergo environmental remediation.