Different Types of Bolts


Bolts are made in a number of variations, and used for a seemingly infinite number of purposes. They have been used throughout history and made from different materials from wood, iron, steel, and even plastic. Hardware manufacturers of today have been able to streamline the bolt industry by designing fewer bolts for a wider range of applications.

Hex Bolts

  • The hex bolt is among the most commonly used fasteners, as its basic shape offers a universal application. This bolt is comprised of a 6-sided head, threaded shaft, and is made from a variety of steel grades. Hex bolts are threaded, and need a matching nut size in order to complete operation. These are commonly used in construction and custom auto applications.

Carriage Bolts

  • The carriage bolt is most commonly used in wood lumber construction for fastening large structural wood members. Carriage bolts are made with a smooth, rounded head, and small cubic section underneath that serves to lock the head in place when tightened. Like the hex bolt, these bolts also have threaded shafts that require the use of a matching threaded nut.

Lag Bolts

  • The lag bolt resembles the hex bolt in that it also has a hex head, but the lag bolt is made with a pointed wood thread shaft and is used for fastening wood without the use of a threaded nut. Before these bolts can be used, a pilot hole must be drilled in the wood to prevent splitting.

Eye Bolts

  • Eye bolts are unlike other bolts as they are made with circular rings instead of a wrench head; these circular heads are used for attaching rope or chain. The eye bolt is also made with pointed lag threads for use in wood without needing a threaded nut. These bolts are most commonly used for hanging heavy fixtures like lighted ceiling units or storage containers.


  • The U-bolt is in the shape of a "U" and is threaded on both ends for the attachment of a metal strap and nuts. The purpose of the U-bolt is for securely attaching pipes or other round objects to structural members, and is also available with a square bend instead for use with non-round objects.

Related Searches


  • Handbook of Bolts and Bolted Joints; John Bickford and Sayed Nassar; 1998
  • Standard Handbook of Fastening and Joining; Robert O. Parmley; 1996
  • What Every Engineer Should Know about Threaded Fasteners; Alexander Blake; 1986
  • Photo Credit "Bridge Maintenance" is Copyrighted by Flickr user: chefranden (Randen Pederson) under the Creative Commons Attribution license.
Promoted By Zergnet



You May Also Like

  • The Types of Wrenches

  • Kinds of Fasteners

    Some fasteners hold two pieces of fabric together; they are used in garment sewing to help the wearer put on and take...

  • Types of Rock Bolts

    Rock bolts are used to support underground excavations. They consist of a long metal shaft that is sunk into the rock and...

  • Types of Screws & Their Uses

    Screws come in a variety of materials such as brass, stainless steel, nylon, aluminum, copper, titanium and ceramic. Screw driving shapes, which...

  • Types of Anchor Bolts

    Anchor bolts are used to attach structures and fixtures to masonry. Light posts, bridge railings and hand rails are examples of items...

  • Different Types of Bolts & Nuts

    When people speak of the "nuts and bolts," they're generally talking about the basics or the practical essentials of something. Indeed, physical...

  • Types of Screws, Nuts & Bolts

    Screws, nuts and bolts are distinguished by their size, diameter, thread count and style of head, such as pan heads, hex heads...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!