Types of Bolts, Nuts and Washers
Choosing the right nut, bolt or washer is an important part of any project as each serve different purposes. In this guide, we’ll show you some of the benefits and differences of various types of bolts and nuts so you can pick the right ones for your project with confidence.
Common Types of Bolts
Bolts are used in all kinds of applications from woodworking to industrial assembly. There are different types of bolts for various jobs, and we’ll show you some of the more common types below.
Carriage Bolts
A carriage bolt has a round, domed head and a square shoulder underneath, preventing the bolt from pulling through or rotating once fastened in place.
Carriage bolts are traditionally used in woodworking, construction and furniture assembly.
Lag Bolts
A lag bolt, or lag screw, is a heavy-duty fastener that is designed for high-strength applications.
They’re typically used to secure heavy materials to wood or carry heavy loads, and are commonly used in decking, framing and other construction projects.
Anchor Bolts
Anchor bolts are specifically designed to secure heavy objects to concrete or masonry surfaces.
The threaded end is embedded in the concrete during the hardening process and then a nut is attached afterward to create a secure connection.
Hex Bolts
A hex bolt has a six-sided head and is designed to be loosened or tightened with a wrench or socket tool to create a secure connection.
Hex bolts are commonly used in construction, machinery and automotive applications.
Eye Bolts
Eye bolts are a type of fastener with a looped end that allows for ropes, cables or other items to be passed through.
Eye bolts are commonly used in rigging, anchoring, hoisting and other applications.
U-Bolts
A U-bolt gets its name from its shape and is threaded on either end. They’re commonly used to attach pipes, tubes or cables to another surface.
U-bolts are often used in construction, plumbing and other projects.
Hanger Bolts
A hanger bolt has a threaded end as well as a wood screw end. It is designed to be drilled into wood or other materials, leaving a threaded end to attach brackets, hooks or other items to.
They’re traditionally used in furniture making, woodworking and other projects.
Plow Bolts
A plow bolt has a flat, countersunk head with a threaded shaft and is designed to sit flat along the surface it’s connected to, minimizing the risk of interference or damage to anything that may run along it.
They’re typically used in machinery applications.
Toggle Bolts
Toggle bolts are used to secure objects to hollow walls or ceilings. When tightened, the wings on the backside expand and grip the wall, securing the bolt to it.
Toggle bolts are typically used to hang heavy objects like shelves on walls.
J-Bolts
J-bolts get their name from their shape and are a type of anchor bolt. The threaded end can be used with a nut or embedded into a concrete surface.
They are used mainly for anchoring purposes, allowing you to hang items from concrete or masonry surfaces.
Common Types of Nuts
A nut is a type of fastener with an internal thread that fits around a bolt or screw to securely hold two objects together. We’ll show you some of the most common types of nuts for your projects.
Cap Nuts
A cap nut, or acorn nut, has a domed top that provides a finished look while protecting the exposed threads from corrosion.
They’re typically used in applications where a finished look is important.
Hex Nuts
The hex nut is one of the most commonly used nuts and is designed to be tightened or loosened with a socket tool or wrench.
Hex nuts are widely used in machinery, construction and various industrial applications.
Jam Nuts
A jam nut is a type of hex nut, but it is typically used alongside it to securely fasten the hex nut into place by “jamming” it, preventing it from loosening due to vibrations or other factors.
Jam nuts are used in automotive, machinery and other applications.
Lock Nuts
A lock nut is used in place of a traditional hex nut to prevent loosening due to vibration or other factors.
Lock nuts are use in applications where secure and reliable fastening is required such as aerospace, automotive manufacturing and more.
Coupling Nuts
Coupling nuts, or extension nuts, are a hollow, threaded fastener that can join two male nut threads and can be driven in with a wrench.
Barrel Nuts
A barrel nut can be inserted into a pre-drilled hole and is designed to be used with a screw to create a secure connection.
They’re commonly used in furniture construction, cabinetry and woodworking projects.
Insert Nuts
Insert nuts are inserted into a pre-drilled hole to create a threaded connection point for screws where there may otherwise not be one.
They’re commonly use in furniture making as well as automotive and aerospace assembly.
T-Nuts
T-nuts (or tee nuts) have a flange at the end of a long threaded body. They typically have 3 or 4 prongs that sink into the material when inserted for better retention and to stop rotation.
They’re commonly used in woodworking and furniture assembly.
Wing Nuts
A wing nut features two “wings” on either side and is designed to be tightened using your fingers, without the use of tools.
Wing nuts are typically used projects where you may need to remove and refasten them multiple times, like fixtures, DIY projects and more.
Flange Nuts
Flange nuts feature a wider flange on the base of the nut, which helps to distribute weight and reduce loosening due to vibration.
They’re typically used in plumbing, automotive and other applications.
Well Nuts
A well nut combines a threaded insert with a rubber outer body, which expands when compressed to create a tight fit that seals the connection and reduces vibrations.
They’re commonly used in automotive, marine and industrial applications.
Push Nuts
A push nut (or retaining nut) is designed with inner-facing teeth that grip into the surface when mounted.
They’re commonly used in automotive, electronic or furniture assembly.
Bolts and Nuts: Things to Consider Before Buying
When considering which nuts and bolts to buy, there are a few major things you should look at.
Material:
The material of your nuts and bolts determines their strength. Common materials are stainless or carbon steel, brass and nylon. Consider the application before selecting your material.
Finish:
Finish will affect the final look of your project as well as the corrosion resistance of your nuts and bolts.
- Zinc - Most common, resists corrosion and rust and is low cost.
- Nickel - Higher investment, but with a very hard finish and high corrosion resistance.
- Chromium – Good rust and corrosion resistance with a bright finish.
- Chromate – Superior rust resistance with a distinct colour and shine.
- Anodized Aluminum - Excellent corrosion resistance and comes dyed in a variety of colors.
Size:
Consider the diameter, thread pitch and length when buying your nuts and bolts to ensure you’ve got the right ones for your project.
Common Types of Washers
A washer is a thin, metal, rubber or plastic disc that is designed to sit between your nut and bolt head to distribute pressure and prevent loosening of the fastener. We’ll show you some of the most common types of washers you can use in your projects.
Flat Washers
Flat washers are the most common and are circular. They help distribute weight and create a more secure connection.
Square Washer
Square washers are similar to flat washers, but they are square-shaped, making them suitable for different applications.
Lock Washers
Lock washers help to prevent loosening of the screw or bolt due to vibration. Split lock washers have a split design that creates tension to keep everything secure. Internal tooth lock washers have teeth that grip into the nut or bolt head to prevent loosening.
Fender Washers
Fender washers have a larger surface area then traditional washers to help prevent damage to the material being fastened.
Spring Washers
Spring washers (also known as belleville or conical washers) are designed to create tension and maintain the tightness of the bolt or screw to provide resistance against vibrations.
Beveled Washers
Bevelled washers have a slope on one side and are commonly used in applications where a flush or recessed appearance is desired.
Finishing Washers
Finishing washers are largely used for aesthetic purposes and provide a finished or decorative appearance when fastening things together.