Bo lt what is

Fasteners with their entire shaft threaded are normally called screws. The unthreaded part of a bolts shaft is called the shank. The shaft of the bolt prevents radial movement of the parts, while the head of the bolt and the nut, if fitted, prevents axial movement.

The unthreaded shank provides an interface with the parts that is more precise and less abrasive. The shank also does not contain stress concentrations that could lead to failure, it is therefore important that the shank extends well beyond the interface between parts if a significant shear force will be placed on the bolt. A bolt fastening a part to another part with a threaded hole, technically in this application it is acting as a screw.

Bolts often rely on axial force causing sufficient friction at the threads to remain in place. A torque is applied to the head to generate this axial force. The force acts between the bolt head and whatever the bolt is screwed into, whether that is a nut or one of the parts being fastened. This causes elongation of the bolt and compression of the parts containing clearance holes. Alternatively some form of locking nut or thread-locking adhesive may be used to prevent the bolt from loosening.

The most common type of bolt is the hex bolt. This has a hexagonally shaped head, providing flat surfaces for tools to apply torque when fastening. An easier to manufacture square head was used for older bolts and this is still used today for applications where very high torque must be applied using a spanner. Many other types of bolts are available for specific applications, for example:.

Bolts are graded according to their strength, using two numbers separated by a point. This grade is often stamped on the head. Have you locked and bolted the door? The door bolts on the inside. Locking and bolting. On a ship the furniture is often bolted to the deck. Fastening and tying. Phrasal verb bolt sth on. I fastened the door with a bolt. Did a bolt of lightning set fire to the barn? Idiom a bolt from the blue. Be sure to bolt the door when you go to bed!

He sat on a wooden bench bolted to the floor. The stall sold bolts of cloth and cheap clothes. The furniture fits together with nuts and bolts. Translations of bolt in Chinese Traditional. See more. Need a translator? Translator tool. What is the pronunciation of bolt? Browse bolshy. Test your vocabulary with our fun image quizzes.

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