ThePipingMart Blog Fasteners Shield Anchor vs Through Bolt – What’s the Difference

Shield Anchor vs Through Bolt – What’s the Difference

Shield Anchor vs Through Bolt

Professionals often opt for anchor fasteners when fixing heavy equipment or machinery to concrete or masonry walls. These fasteners are commonly utilized in construction, industrial, and commercial settings all around the world. But what kind of anchor should you use? Two of the most popular options in the concrete anchor world are the shield anchor and through bolt. Both are known for their stamina and durability, but why are they different? In this blog, we will discuss the differences between shield anchors and through bolts and help you determine which option is best for your construction project.

What is Shield Anchor?

Shield Anchor is a masonry anchor that provides a secure fixing point into brick, stone or concrete. It has an expansion shield at its base and is secured by driving the wedge-shaped expansion wedge behind the shield using special tools such as a hammer or power tool. The shield anchor’s strength and holding power increase over time due to its secure fitting within the substrate. It is ideal for scenarios where high loads are expected in multiple directions, making it great for suspending heavy equipment such as lighting fixtures and security cameras.

What is Through Bolt?

A through bolt is a fastener typically used to securely attach two pieces of metal. It consists of a long, threaded shank that passes completely through the connected parts and has a nut and washer attached at the far end. Unlike screws and nails, which make contact only on one side, through bolts allow even pressure to be distributed across both components, making them ideal for use in applications where high strength is required. This makes them suitable for tasks such as structural steelwork or retaining walls.

Difference Between Shield Anchor and Through Bolt

Material Composition

A shield anchor is made of a metal sleeve that expands when you tighten the bolt. This creates a secure, pressure contact point for the fixture to be attached to. The sleeve is fastened in the hole using hammering or spinning the sleeve with a hammer drill; this, in turn, helps the sleeve wedge against the sides of the hole as a securing element. In contrast, a through bolt has a hardened steel bolt that passes completely through the fixture into the concrete, where it expands through a mechanical process of torque. The bolt wedges to the sides of the hole and compresses the material between the bolt and sleeve, creating a tight grip.

Performance and Limitations

The performance of a shield anchor is dependent on the size of the hole, the length of the internal sleeve and the torque applied during installation. It can be used for lightweight to medium loads of fixtures. Due to its design, it is only suitable for dry, compressed materials and not wet materials. In contrast, the through bolt has improved performance and is often used to fasten heavy pieces of equipment. Additionally, the through bolt can be used in wet materials and has a higher tensile load of up to five times more than a shield anchor, making it the right choice for more significant construction projects and heavy-duty applications.

Installation Process

Installation of a shield anchor requires drilling an accurate hole to the correct depth and diameter. The correct size hole allows the anchor to do its job correctly, and if the hole is too wide, the anchor may not work correctly or become loose. Once the hole is drilled, the sleeve is driven in with a hammer drill, and the bolt is then tightened to the recommended torque. Similarly, through bolts also require precise hole drilling of the right size in terms of diameter and depth. After implanting the bolt, a torque-kinetic energy tool is used to complete the fixture’s fastener installation.


The primary benefit of shield anchors is that they are better suited for lightweight fixtures, and they are easier to install than through bolt anchors. However, the disadvantage is that they do not have high tensile strength compared to through bolts, which means they cannot support significant weight. On the other hand, through bolts have a more substantial load capacity, making them suitable for hardy applications. 

Cost Implications

Shield anchors are often smaller, less strong and cheaper than through bolts, making them more affordable and perfect for light-duty applications. Nevertheless, when deciding which of the two to use, it’s essential to include bolt quality, length, and drill bits. Through bolts are often sold with the bolt and fixture, but if you need to purchase them separately, they’re a bit more expensive.


Shield anchors and through bolts have varying strengths, weaknesses, and applications. While both are ideal when it comes to fixing heavy equipment or machinery to concrete or masonry walls, the choice of which to use depends on many factors, such as the size of the fixture or equipment and the purpose of the structure, among other factors. The best way forward is to understand the differences between shield anchors and through bolts and match the construction application’s requirements with the right type of fix mechanism. Making this informed decision will ensure that your structures are safe and secure.

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