Different Types of Bolt Heads and Their Uses

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. In this reading, we’ll explore the various types of bolt heads and their uses.

Let’s begin!

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Types of Bolt Heads

Below are the various types of bolt heads:

• Flat bolt head
• Oval bolt head
• Pan bolt head
• Truss bolt head
• Round bolt head
• Hex bolt head
• Hex washer bolt head
• Slotted hex washer bolt head
• Socket cap bolt head
• Button bolt head

1. Flat bolt head: a countershank head with a flat top.
2. Oval bolt head: a countershank head with a rounded head top.
3. Pan bolt head: a slightly rounded head with a short vertical side.
4. Truss bolt head: an extra-wide head with a rounded top.
5. Round bolt head: a Dome’s head.
6. Hex bolt head: A hexagonal head.
7. Hex washer bolt head: a hexagonal head with a round washer at the bottom.
8. Slotted hex washer bolt head: a hexagonal head with a built-in washer and slot.
9. Socket cap bolt head: a small cylindrical head using a socket driver.
10. Button bolt head: a low-profile rounded head with a socket driver.

Conclusion

While screws and bolts have much 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.

Bolt heads are the shaped ends of bolts designed for tightening or loosening using tools like wrenches or spanners. They come in various shapes—hex, square, round, socket, and more—each suited for specific applications.

Choosing the right bolt head ensures easy installation, secure fastening, and structural integrity. From automotive to construction, bolt heads play a crucial role in mechanical joints.

Frequently Asked Questions (FAQs)

What is a bolt head?

A bolt head is the top portion of a bolt that allows for tightening or loosening using tools.

What are the most common types of bolt heads?

• Hex head (6 sides)
• Square head (4 sides)
• Round head
• Socket head (internal drive)
• Flanged head

Why are hex heads so common?

Hex heads provide a good grip, can be turned with a variety of tools, and are effective in tight spaces.

What is the difference between a bolt head and a nut?

A bolt head is fixed and used for tightening the bolt, while a nut is threaded onto the other end to secure components together.

When should I use a socket head bolt?

Use socket head bolts when you have limited external space and want to tighten the bolt from inside using an Allen wrench or hex key.

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What is a flanged bolt head?

It has a built-in washer at the base of the head to distribute pressure and reduce the chance of loosening.

Can bolt heads affect the strength of a joint?

Yes. The design and shape of the bolt head can impact the clamping force, load distribution, and ease of maintenance.

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?

• Anchor Bolts.
• Blind Bolts.
• Carriage Bolts.
• Double-End Bolts.
• Eye Bolts.
• Flange Bolts.
• Hex Bolts.
• Machine Bolts and Machine Screws.

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?