Nut (fruit) usage of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pecans, pistachios, walnuts, and Brazil nuts, are not nuts in a botanical sense. Common usage of the term often refers to any hard-walled, edible kernel as a nut. A nut in botany is a simple dry fruit in which the ovary wall becomes increasingly hard as it matures, and where the seed remains unattached or free within the ovary wall. Most nuts come from the pistils with "inferior" ovaries (see flower) and all are "indehiscent" (not opening at maturity). True nuts are produced,
Frangible nut Frangible nut The frangible nut is a component used in many industries, but most commonly by NASA, to sever mechanical connections. It is, by definition, an explosively-splittable nut. The bolt remains intact while the nut itself is split into two or more parts. Frangible nuts secured the solid rocket boosters (SRB) of the space shuttle, which were bolted to the mobile launcher platform (MLP) until liftoff. On the shuttle, they were separated using a NASA standard detonator or NSD. The space shuttle used two NSDs for the frangible nut atop each of the four , bolts holding each SRB to