There are many different head shapes for both screws and bolts. The design of these heads allows them to easily grasp the instruments needed to tighten them. A bolt is a long piece of metal used to attach items by screwing them into a nut. When you bolt anything to another object, you use a bolt to fasten them together firmly.

Depending on your project design, you can design specific bolt heads for your project which can be done by a Finnish company called Kuusamon Uistin, located in Kuusamo Finland. They manufacture arctic ski bindings for outdoor and military purposes. They are looking to source a specific kind of screw in a quite big volume over the next few years.

Well, in this article, you’ll learn the different types of bolt heads. Well, in this article, we’ll be discussing the common types of bolts and bolt heads available in the market today.

different types of bolt heads


What are the types of bolts?

The followings are some important types of bolts with their head shapes:


These types of bolts have a T-shaped head in order to be held by a wrench or to be easily fixed in place. Provides a long-lasting connection. They are used in buildings, instruments, furniture, automobiles, etc.

Timber bolts

Timber bolts are sometimes referred to as mushroom head bolts or dome head bolts. Treated lumber, marine applications, and wood construction.

Toggle bolts

Toggle bolts are sometimes called butterfly anchors. Full threaded shafts with a nut in the shape of an expanding wing. They are used for hanging heavy elements in plaster and drywall.


U-bolts have the shape of a letter U. They are threaded on both ends and non-threaded in curved sections. Their primary use is to support pipework, especially pipes via which liquids and gases flow.

Flange bolts

Flange bolts are washers on the underside of a hex head. They help in the distribution of force from the bearing load. Also referred to as frame bolts. flange types of bolts are used on frame applications such as truck and bed frames.

Flange bolts

Hanger bolts

Hanger bolts do not come with a bolt head. This is to say, both ends of the bolt are threaded. One of the ends is in the shape of a wood screw. Hanger types of bolts are used in overhead applications and fastening metal to wood.

Hanger bolts

Hex bolts

Hex bolts are bolts that are fully or partially threaded with six-sided heads. Their broad range of use includes the construction and repair of bridges, docks, highway elements, and buildings.

Hex bolts

J bolts

J bolts have a shape like a letter J. Non-curved section is threaded Structural applications such as fastening walls to concrete.

J bolts

Lag bolts

Lag bolts are one of the toughest types of fasteners. It creates its own thread when it penetrates the wood and other soft material. These types of bolts connect heavy materials that are bearing extreme loads.

Lag bolts

Machine bolts

Machine bolts consist of square heads paired with a semi-cone point and a fully threaded shaft. They can be used to fasten wood to wood, wood to metal, and metal to metal. They can also be used in general hardware.

Machine bolts

Plow bolts

Plow bolts are similar to carriage bolts. They have a countersunk flat head followed by a square undercut and a threaded shaft. plow types of bolts are used in applications where the top surface of where the bolt is fastened needs to be smooth. They are often used in the manufacture of plows in the early days.

Roof bolts

Roof bolts are made of a shaft that is to be placed in a pre-drilled hole. They are used in tunneling and underground mining. These types of bolts can also provide support to the roof.

Anchor bolts

bolts having an L-shaped part that isn’t threaded on one end and a threaded portion on the other. commonly seen with a washer and a nut. designed to withstand corrosion. These types of bolts are used to anchor equipment to concrete as well as to hold light poles, structural beams, and other objects.

Anchor bolts


Carriage bolts

Fully threaded carriage bolts have a smooth head and a square or ribbed undercut that, when the bolt is tightened, prevents it from rotating. Frequently, they are used to fasten metal to wood.

Carriage bolts

Elevator bolts

Elevator bolts are Fasteners with a square undercut that stops the bolt from rotating when it is tightened and a thin flat or countersunk head. they are utilized in conveyor systems and elevators.

Elevator bolts

Eye bolts

The eye bolts are rod-shaped fasteners with threads on one end and bent into a loop on another. They are suitable for lifting applications such as wire and rope in light rigging.

Eye bolts

Shoulder bolts

Shoulder bolts are also known as shoulder screws. They consist of a long unthreaded, cylindrical shank that helps the rotation of attached moving parts. They are used in pulleys, moving engine parts and mechanical assemblies, gears, and rolling wheels.

Square head bolts

Square bolts have square heads, followed by a smooth shank and a machine screw thread. They can also be fully threaded with the absence of a smooth shank. The design of the head facilitates easier wrench grip when tightening. These types of bolts are used in all kinds of industrial, agricultural as well as construction applications.

Step bolts

The shank of a step bolt may be plain or textured. It is a high-strength, threaded bolt used as steps for climbing on steel communication and electrical transmission towers.

Structural bolts

Structural bolts are similar to the standard hex head bolts but have shorter thread lengths, in order to be used in structural applications. These types of bolts can be used in all types of structural connections.


Types of bolt heads

Bolt heads come in various shapes, with square, hex, and slotted hex washers, and socket caps being the most popular. The square head bolts were the first to be used. Square heads are composed of a shaft that can withstand rotation when a torque is applied, followed by a square depression on the head.

Hex heads have become more prevalent, however square heads are still in use. To provide torque, hexagonal heads are used with a wrench or a spanner.

Types of bolt heads

Other types of bolt heads

Flat bolt head – A counter shank head with a flat top.

Oval bolt head – A counter shank head with a rounded head top.

Pan bolt head – A slightly rounded head with a short vertical side.

Truss bolt head – An extra-wide head with a rounded top.

Round bolt head – A Dome’s head.

Hex bolt head – A hexagonal head.

Hex washer bolt head – A Hexagonal head with a round washer at the bottom.

Slotted hex washer bolt head – A hexagonal head with a built-in washer and slot.

Socket cap bolt head – A small cylindrical head using a socket driver.

Button bolt head – A low-profile rounded head with a socket driver.


What is a bolt head called?

The head of a bolt refers to the upper portion of the bolt, not the threaded end. Bolt heads come in a variety of shapes and sizes, and they may all be twisted with a spanner or driver. The bolt’s threaded end has a helical ridge that enables rotation inside a threaded nut.

What are the types of bolts?

What are the 4 parts of a bolt?

Runout: The point on the bolt where the thread “runs out” and the shank starts. Shank: The bolt’s smooth, threadless portion. Radius: The arc that connects the head with the shank. The portion of the bolt that a torque tool may hold to tighten or loosen it is called the head.

What are bolts with Allen heads called?

Allen head screws or bolts, commonly known as socket screws, are fastened using a hexagonal or shaped wrench and require a key to tighten and unfasten. Standard sizes are readily accessible. Typically, machine parts, die fixturing, and clamping require socket head cap screws.

What are the three types of bolts?

In order to secure or bind things together, a threaded bolt screws into nuts. Eye bolts, wheel bolts, and machine bolts are examples of a bolt type, and cap nuts, expansion nuts, and u-nuts are examples of a nut type. You will learn about the various sorts of nuts and bolts in this article, as well as the various varieties of bolt heads.

What is a bolt without a head called?

Rod with threads. A threaded rod has no head and is available in a variety of grades and materials. Threaded rod, also known as redi-rod, fully threaded rod, and ATR, is used to fasten everything from anchor bolts to hanging piping or electrical equipment from ceilings.

Which bolt is used most commonly?

The Most Common Types of Bolts


While screws and bolts have a lot in common, there are also some key distinctions. That is all for this article, where the most common types of bolts and bolt heads are discussed. Check out the various types of bolts and screws below. I hope you learned from the reading, if so, kindly share it with others. Thanks for reading, see you around!