Dynamite is usually sold in the form of a stick about 8 in (20 cm) long and about 1.25 in (3.2 cm) in diameter, with a weight of about 0.5 lb (0.23 kg). Other sizes also exist. Maximum shelf life of nitroglycerin-based dynamite is recommended as one year from date of manufacture under good storage conditions.
Dynamite is a high explosive, which means it detonates rather than deflagrates. While TNT is used as the standard for gauging explosive power, dynamite has more than 60% greater energy density than TNT.
Another form of dynamite consists of nitroglycerin dissolved in nitrocellulose and a small amount of ketone. This form of dynamite is similar to cordite, and is much safer than the simple mix of nitroglycerin and diatomaceous earth. Military dynamite achieves greater stability by avoiding nitroglycerin. Public knowledge of dynamite led to metaphoric uses, such as saying that a particular issue "is political dynamite"
Dynamite was invented by Alfred Nobel and was the first safely manageable explosive stronger than black powder. Nobel obtained patents for his invention: in England on 7 May 1867 and in Sweden on 19 October 1867. He originally sold dynamite as "Nobel's Blasting Powder". After its introduction, dynamite rapidly gained popularity as a safe alternative to gunpowder and nitroglycerin. Nobel tightly controlled the patent, and unlicensed duplicators were quickly shut down. However, a few American businessmen