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,
Speed nut vibrations. There are many different types of speed nuts, mostly dependent on the shape of the nut, how it attaches to the workpiece, and what type of screw can be used. Most types are designed for either machine screws or sheet metal screws. Some nuts do not attach to the workpiece. These are usually shaped as either a rectangle, a flange nut, or a hex nut; the rectangular speed nut is also known as a flat-style speed nut. Speed nuts that attach to the workpiece usually are some form of a J-nut or U-nut. The speed nut was invented by