Carriage Bolts
Carriage Bolts are a form of a self-locking bolt that affords a level of security by using a flush-mount domed head, which permits access to remove or loosen these bolts from the nut side of the bolt only.Beneath the domed head of the carriage bolt is a square section that can be inserted into a corresponding square cut that is slotted in the material being joined so as to provide the self-locking feature that allows the bolt to be tightened from the nut side without a need to restrain the head with a wrench.
Hex Bolts
Hex bolts, also called hexagon head bolts or hexagonal head bolts, are a very common form of bolt that is available in standard dimensional inch and metric sizes. Hex bolts are often used to fasten wood to wood, metal to wood, or metal to metal. Hex nuts and washers are typically used with hex bolts, the washers being valuable for situations where the material being joined is softer and may deform under the tightening force applied to the hex bolt.
U-Bolts
U-bolts are fasteners that are in the shape of the letter U, which contain two male threads, one on each end of the bolt on to which a mounting plate bracket and attachment nuts are placed. While most U-bolts feature a semi-circular profile, some have a squared-off shape.These fasteners are typically not fully threaded, as they function to clamp an object in place. They are used in a range of applications from supporting pipe to automotive use on drive shafts and exhaust systems. Some designs include rubber coating to preclude wear from the movement of metal against metal.Other designs of U-bolt add thick rubber gaskets to reduce the effect of vibration and to control noise. Non-metallic designs are also available for use in applications where there is a risk of the U-bolt making contact with an electrically powered conductor.
Lag Bolts
Lag screws are some of the toughest fasteners. These extremely sturdy fasteners are usually used to connect heavy lumber or other heavy materials that are bearing an intense load.These screws differ from normal wood, self-drilling or sheet metal screws. Compared to most ordinary screws, lag screws are massive in size. Most lag screws are at least one inch long and ¼-inch thick.
T-Head Bolts
T-head bolts or T-slot bolts feature a head design that enables it to be inserted into a slot or recess, thereby securing the bolt in place to prevent it from turning when the securing nut is tightened.T-bolts are used in applications such as securing fuel tanks in place where having access to both sides of the fastener may not be possible in all cases. The T-slot variety of T-head bolt can be fed into a channel in a machine called a T-slot track and may be used to secure an object at any position along the length of the channel.
Socket Head Bolts
Socket head bolts feature a recessed head that is tightened using an Allen wrench or hex socket tool. The head style of these bolts can vary from a cylindrical profile to a flat-head countersunk style to a domed button head design, depending on the desired use.The deeper recessed Allen socket head affords the ability to increase the torque applied to these fasteners while minimizing the risk of stripping or damaging the head. Socket head bolts are often referred to as socket head cap screws, depending on the supplier.
Shoulder Bolts
Shoulder bolts, also called stripper bolts, feature a threaded bolt section of smaller diameter than the shoulder of the bolt (the section of the bolt between the head and the beginning of the threaded portion).Shoulder bolts are useful for functioning as a shaft or axle that can contain a rotating part, such as a bearing or a bushing.
Penta-Head Bolts
Penta-head bolts are an example of a tamper-resistant bolt, which may be used in applications where it is desired to reduce the likelihood that a person armed with standard tools can loosen or remove the bolt.With the head of the bolt in the shape of a pentagon, a standard wrench or socket set will be incapable of being used on these bolts.
Round Head Bolts
Similar in appearance to carriage bolts, round-head bolts do not have the square taper beneath the domed head of the bolt and are typically used to join wood. The softer nature of wood permits the bolt to compress against the surface of the wood and grip by friction to preclude the bolt from turning when the nut is tightened.
Flange Bolts
Flange bolts, also known as frame bolts or serrated flange bolts, have a wide, flat surface under the hex head that acts as a washer, providing extra support and distributing the load evenly. They are often used in automotive and machinery applications.