What Is An Expansion Bolt Used For?
What Is An Expansion Bolt Used For?
Expansion bolts, also known as wedge anchors, are heavy-duty fasteners used to secure heavy objects to walls or floors.
They are made of galvanized carbon steel screws with nuts and washers and feature a yellow passivation coating that makes them rust-resistant. Expansion bolts require a spanner or socket wrench to fasten or undo the bolt.
Expansion bolts work by tightening the bolt, which causes the nut on the opposite end to pull into the shell and expand outward, wedging it inside the hole in the wall or floor. This allows them to handle both vertical and horizontal loads.
Expansion bolts can also be used in walls or floors to enable rope or cable to be threaded through or tied to it, for example, for hanging pot plants or making a clothesline between two walls.
Additionally, expansion projecting bolts allow for the installation of an anchor and then placing an object over the stud where it can be fastened.
What Is The Difference Between An Anchor Bolt And An Expansion Bolt?
An anchor bolt is a type of fastener used to secure an object or structural component to a concrete surface. There are two main types of anchor bolts: cast-in-place and post-installed. Cast-in-place anchor bolts are installed inside a cavity of a concrete surface before the concrete sets.
Post-installed anchor bolts consist of a similar design as cast-in-place anchor bolts, but they are installed after the concrete has been set.
An expansion bolt is a type of post-installed anchor bolt because it’s installed in a pre-drilled hole. Expansion anchor bolts expand when installed inside of concrete, and they require drilling a hole into the concrete before installation.
Expansion anchors can be classified as either torque-controlled or displacement-controlled anchors, depending on how they expand when torqued.
Torque-controlled expansion anchors must be torqued to expand wedges, while displacement-controlled anchors require impact energy to expand wedges.
What Is The Advantage Of An Expansion Bolt?
The main advantage of expansion bolts is their strength and reliability. Expansion bolts are designed to resist loading in both tension and shear, making them suitable for structural connections.
They also have more surface contact inside the hole than a wedge bolt, making them stronger in both pullout and shear strength.
Expansion bolts are also flexible and pliable, allowing them to be used in applications where standard threading cannot be created.
Additionally, they are easy to install with basic tools and require no protrusion when installed with a flush-fit head variant.
Finally, they can hold up to 50 lbs when installed with a molly bolt, making them suitable for heavier items.
What Are The Parts Of An Expansion Bolt?
An expansion bolt consists of three fastening components: an expanding sleeve, a threaded bolt, and a properly sized nut.
There are two kinds of expansion anchors; pre-expanded and unexpanded, with the former being used to connect structural and non-structural elements to concrete.
Expansion bolts for hollow structural steel sections consist of a bolt, an expansion sleeve, and a cone-shaped nut that expands when tightened.
