Bolts

Bolts are threaded fasteners that are used to join and fasten materials together and are normally used together with a nut. They have a cylindrical stem with external threads on one end and a head on the other end so that it can be screwed or unscrewed with the help of a key or screw driver. Bolts are used to give a rigid and firm joint that can be subjected to tension or shear forces, and therefore used in construction, machinery, automotive industries and many others.

Different types of Bolts

There are different types of bolts and each type is intended for a certain purpose and with certain characteristics. Here are some common types of bolts:

Hex Bolts: These are also termed as hex cap screws, they have hexagonal head and are used in construction and machinery for strong and tight fastening.
Carriage Bolts: Carriage bolts are characterized by a rounded domed head with a square neck below it; they are employed in wood to wood, or wood to metal applications where one side of the fastener’s head does not need to be concealed.
Lag Bolts: These are heavy duty bolts with hex head and coarse thread suitable for joining heavy lumber or fastening other materials to wood.
Eye Bolts: These bolts are characterized by a looped head or an “eye” through which cables, ropes or chains can be connected to a structure or an object.
U-Bolts: These bolts are ‘U’ shaped and have threads on both ends and are normally used to attach pipes or tubes to a surface or to hang items.
Anchor Bolts: Intended to be fixed in concrete or masonry, anchor bolts are used to fix structural members such as columns and beams to the foundations.
Flange Bolts: These bolts have a washer-like flange under the head which helps to spread the load over a larger area and thus giving a strong and stable joint.
Shoulder Bolts: These bolts are also referred to as stripper bolts and have a smooth unthreaded region between the bolt head and the external threaded portion and are mainly employed in applications where the bolt works as a guide or a pivot point or as a sliding member in a piece of machinery.
J-Bolts: These bolts are of ‘J’ shape and are used for fastening objects to concrete or other massive structures and are used in foundation works or as hooks for other accessories.
Machine Bolts: Machine bolts are used with nuts or tapped holes with square or hexagonal head for accurate work where a threaded fixing is needed.

All the bolts are uniquely designed to fit certain requirements in different areas.

Different Bolts Materials

Bolts are made from a wide range of metals depending on the need of the application that is to be met. Common materials for bolts include:Common materials for bolts include:

Carbon Steel: Carbon steel is the most common material for bolts due to its relatively low cost, good strength and durability. These carbon steel bolts are used for general purposes and can be of low carbon steel, medium carbon steel or high carbon steel based on the load required.
Stainless Steel: Generally, stainless steel bolts are highly resistant to corrosion and therefore suitable for application in areas with high humidity or chemical exposure or outside environment. Some of the grades include 304 and 316 stainless steel that is widely used in different industries.
Alloy Steel: Bolts manufactured from alloy steel contain other ingredients such as chromium, molybdenum or vanadium to improve strength, tenacity and abrasion resistance. They are employed in conditions where high stress and high temperature are involved like in automobile and aircraft.
Brass: Brass bolts are resistant to corrosion and are not magnetic and hence are suitable for electrical, plumbing, and decorative applications. They are also used in conditions where there is a requirement of low friction and resistance to corrosion from water and some chemicals.
Aluminum: Aluminum bolts are light in weight and do not corrode easily; they are used in areas where weight is a consideration, for instance in the manufacture of aircrafts, automobiles and electronics. They also provide good conductivity thus making them ideal for electrical uses.
Titanium: Titanium bolts are used in aerospace industry, medical implants and marine applications because of their high strength to weight ratio and high corrosion resistance. They are suitable for use in areas where strength and corrosion resistance are important but due to their high costs, they are only useful in certain applications.
Inconel: A high-temperature nickel-chromium alloy used where corrosion by aggressive environment is likely to occur. Inconel bolts are used in conditions that are very high in temperature like jet engines, gas turbines and chemical processing equipment.
Monel: A nickel-copper alloy with high resistance to corrosion in seawater and in acidic solutions. Monel bolts are used in marine and chemical processing industries.
Silicon Bronze: These bolts have fairly good corrosion resistance and are well suited for marine applications such as boat building and construction, coastal construction and where the bolts need to be electrically conductive and non-magnetic.

These materials are selected depending on the strength, environment, corrosion, and special application of the specific product.

Features of Bolts

Here are several key features of bolts:

Threaded Shaft: Bolts are fasteners that have a threaded cylindrical shaft that screws into a nut or a threaded hole to provide a clamp like connection. The threads are cut to match the particular nuts or holes that they are intended to screw into or bolt onto.
Head Type: Bolts have different types of head shapes (hexagonal, square, round etc. ) through which different types of tools can be used to either tighten or remove the bolts. The head type determines how the bolt can be easily fixed and removed and its ability to meet certain applications.
Material Strength: Bolts are manufactured from carbon steel, stainless steel or alloy steel, which define the load bearing capacity of bolts. Grades and material have a difference in tensile strength and durability of the products.
Corrosion Resistance: A large number of bolts are protected against corrosion by applying a specific treatment or coating to prevent their degradation by moisture, chemicals and salts. Some of the coatings are zinc plating, galvanizing or employing corrosion resistant materials such as stainless steel.
Durability: Bolts are manufactured to bear mechanical loads for example tension, shear and vibration forces. Superior quality bolts do not degrade in performance even under conditions of high stress and thus provide consistent fastening.
Versatility: Bolts are available in different sizes, lengths and threads and that makes them suitable for many uses. It can be applied in construction, automotive industry, machinery industry and electronics industry etc.
Ease of Installation: A lot of bolts are intended to be easily installed and removed by hand or with simple hand tools such as wrenches or sockets. Some bolts are also intended for certain tools or equipment so that they can be used with relative ease in certain applications.

Such features make bolts suitable for use in a wide range of industries and in different applications.

Applications of Bolts

Bolts are one of the most important types of fasteners that can be used in a number of industries and fields. Here are some common applications of bolts:

Construction: Bolts fasten structural members in buildings and bridges like beams, columns and plates. They offer good, durable bonds that are capable of bearing the forces and loads that are common in construction.
Machinery and Equipment: In industrial machinery, bolts are used to hold together and to fix different parts like gears, motors, and frames among others. They are used for purposes of maintaining the mechanical structures and the efficiency of the machines.
Aerospace: Bolts are employed in aircrafts and spaceships for fastening and joining parts such as wings, engines, and fuselage sections. Aerospace bolts are required to possess high strength and lightweight as well as the ability to withstand various harsh environments.
Marine: Bolts are applied in shipbuilding and offshore platforms to fasten parts that are subjected to extreme marine conditions. They should not corrode from seawater and they should be capable of giving a secure fastening under dynamic loading.
Electronics: In electronics industry bolts are used to join and fasten parts in computers, servers, telecommunication equipment among others. They hold together electronic enclosures and mounting systems to ensure they are not compromised in their structure.
Furniture: Bolts are employed in construction of furniture like beds, tables and cabinets among others. They offer strong joints and can be disassembled and assembled in case they are required to be moved from one location to another.
Oil and Gas: Bolts are employed in drilling rigs, pipelines and processing facilities to fasten flanges, valves and other related parts. They are required to be able to endure high pressures, heat and chemical solutions.
Railway: Bolts are applied in rail construction and in the construction of rolling stock, to fasten rail parts, wheels and other components. It has to support large quantities and withstand abrasion from constant motion.

In each of these applications, bolts are vital in that they guarantee the holding together of parts so that they can function as intended under different circumstances.