Conventional blasting caps use electricity to heat a bridge wire rather than vaporize it, and that heating then causes the primary explosive to detonate. Imprecise contact between the bridgewire and the primary explosive changes how quickly the explosive is heated up, and minor electrical variations in the wire or leads will change how quickly it heats up as well. The heating process typically takes milliseconds to tens of milliseconds to complete and initiate detonation in the primary explosive. This is roughly 1,000 to 10,000 times longer and less precise than the EBW electrical vaporization. Use in nuclear weapons Since explosives detonate at typically 7–8 kilometers per second, or 7–8 meters per millisecond, a 1 millisecond delay in detonation from one side of a nuclear weapon to the other would be longer than the time the detonation would take to cross the weapon. The time precision and consistency of EBWs (0.1 microsecond or less) are roughly enough time for the detonation to move 1 millimeter at most, and for the most precise commercial EBWs this is 0.025 microsecond and about 0.2 mm variation in the detonation wave. This is sufficiently precise for very tight tolerance applications such as nuclear weapon explosive lenses. In the US, due to their common use in nuclear weapons, these devices are subject to the nuclear control authorities in every state, according to the Guidelines for the Export of Nuclear Material, Equipment and Technology. EBWs are on the United States Munitions List, and exports are highly regulated. Civilian use EBWs have found uses outside nuclear weapons, such as the Titan IV, safety conscious applications where stray electrical currents might detonate normal blasting caps, and applications requiring very precise timing for multiple point commercial blasting in mines or quarries. EBW detonators are much safer than regular electric detonators because unlike regular detonators EBWs do not have primary explosives. Primary explosives such as lead azide are very sensitive to static electricity, radio frequency, shock, etc. Mechanism of operation The bridgewire is usually made of gold, but platinum or gold/platinum alloys can also be used. The most common commercial wire size is 0.038 mm (1.5 mils) in diameter and 1 mm (40 mils) in length, but lengths ranging from 0.25 mm to 2.5 mm (10 mils to 100 mils) can be encountered. From the available explosives, only PETN at low densities can be initiated by sufficiently low shock to make