Masonry screw anchors

Types of masonry screw anchors

• Concrete screws

  Concrete screws are a common choice of masonry screw anchor and are concrete or brick used. They are made of hardened steel, and these screws have vertical flutes or threads that cut through concrete and provide a very tight grip. The installation of concrete screws is fairly straightforward since they can be fixed with a power/hammer drill and don’t require any extra fixing work. Their most common use is for attaching windowsills, door frames, and slabs and fixing steel supports and other materials to concrete walls, floors, and ceilings.

• Expansion anchors

  Expansion anchors are another popular type of masonry screw anchor suitable for solid and hollow masonry. These anchors consist of a bolt and an expanding sleeve that is inserted into the drilled hole in the masonry. Any movement or tightening of the bolt causes the sleeve to expand to the sides of the hole, thus providing a very firm and load-bearing fit.

  Expansion anchors are commonly utilized to fix structural steel frames, pulleys, and sheaves and for heavy suspended work like ceilings and walls. Some types have also been rated for use in seismic regions and with heavier loads.

  The expansion style is generally classified based on masonry units: those are suitable for solid materials. Standard expansion anchors are for concrete, brick, and block. Hollow wall anchors are for thin walls like drywall or hollow bricks.

• Wedge anchors

  Wedge anchors are permanent high-strength fasteners fixed to the surface of concrete, brick, or block walls. The anchor comprises a threaded bolt with a wedge-shaped end that is driven into the concrete, causing it to expand and create a grip.

  Due to their grip and load capacity, Wedge anchors fix heavy loads like guardrails, column bases, lifting eyes, and machines to concrete walls and supported floors.

• Sleeve anchors

  Like expansion anchors, sleeve anchors also have an expanding mechanism that allows them to download structures like brackets from the wall to the supporting concrete floor. Sleeve anchors, however, differ in being more flexible in mounting because they can also be used on non-concrete materials like sandstone and other brittle rocks. Sleeve anchors and their corrosion-resistant stainless steel variants are commonly used for mounting equipment in outdoor and marine atmospheres.

How to Choose masonry screw anchors

When selecting masonry screw anchors, buyers consider the following:

• Material compatibility: Different anchor types are suitable for different masonry materials. Concrete screws perform well on hardened concrete. In comparison, expansion anchors are better for both hollow and solid masonry. Wedge anchors are high-strength options for securing heavy loads on concrete or masonry.
• Load requirements: Assess the shear and tensile load that will be exerted on the anchor when it is in a fixed position. Higher load-bearing capacity anchors, such as wedge or sleeve, are better suited for heavy-duty fixed applications. More than one anchor can be used for even load distribution, where required.
• Corrosion resistance: If the application is outside or in a corrosive atmosphere, opt for corrosion-resistant materials like stainless steel or galvanized steel of the masonry anchors. Many expansion and sleeve types are also weatherproof.
• Easy installation: Some multiline anchors, like concrete screws, require less fixation effort than expansion and sleeve anchors, which need drilling and inserting the sleeve. If the installation time needs to be minimized, such anchors are better.
• Adjustability: Some anchors like the toggle are adjustable, which could provide better convenience in applications where the load needs to be mounted or aligned provisionally.
• Spacing and depth: Consider the required spacing between anchors used on structural fixings and the depth of the fixings. The same goes for the drilling through the concrete or masonry for the anchor. Certain types can be longer or shorter to go deeper or shallower into the material.

Application of masonry screw anchors

Masonry screw anchors serve a variety of functions in construction and repair:

• Heavy loads: Masonry Screw anchors are primarily used when fixing heavy loads to concrete or masonry. They are designed to handle high shear and tensile forces and fix items like structural beams, electrical conduits, piping, anchors, and other heavy mechanical equipment firmly onto concrete floors and walls. They distribute the load across a wide area to prevent the carried weight from pulling out or causing damage to the underlying masonry over time.
• Securing outdoor fixtures: The expansion and concrete screws are corrosion-resistant and so are suitable for outdoor applications like securing handrails, flagpoles, lighting fixtures, and signs fixed to concrete walkways and patios, sidewalks, etc., and exposed to weather elements. Even after some years, these anchors still provide a level of stability under the wind, rain, and temperature variation that persuaded them not to pull out or decay.
• Non-structural partitions: Masonry screw anchors hold partition walls, ceiling grids, and fixtures like shelves, cabinets, and racks that don't carry the structural load directly but still need a strong fixing to a concrete or masonry foundation. They provide enough stability to support the weight of these items without sagging or toppling over, thus giving a neat and reliable interior design.
• Mechanical and plumbing systems: Masonry screw anchors secure piping systems, ventilation ducts, and plumbing infrastructure to concrete walls and ceilings. This keeps these systems properly aligned and enabled them not to move or vibrate out of place during their functioning, hurting their performance maintenance-wise and aesthetically.
• Industrial applications: In warehouses, factories, and other industrial environments, masonry screw anchors fix racks, conveyor systems, machinery, and other equipment to concrete floors. They ensure these materials remain safely in place, preventing uneven wear and disrupting operations with movement or tipping over.

Advantages of masonry screw anchors

• Strong holding power

  The primary advantage of anchor bolts is their strong holding power due to the mechanical locking from their threaded design and compression fit against masonry. This enables them to carry huge shear and pull forces, establishing a fixed connection for heavy items like structural beams, machinery, and equipment to concrete walls or floors.

• Corrosion resistance

  Certain Masonry screw anchors, specifically concrete screws and sleeve anchors, are often made of corrosion-resistant materials such as stainless steel or galvanized steel. As such, they will be fixings for outdoor applications or inside environments like factories, including moisture or chemical exposure.

• Versatility

  Concrete screws, expansion, and sleeve anchors have different masonry screw anchors that provide a stringent fit on concrete, brick, block, or stone. This makes them highly versatile fixings to mount items on a variety of hard substrates and across various applications, such as construction, maintenance, and manufacturing.

• Ease of installation

  Among the advantages of screw anchors is ease of installation. Most masonry screws require only a hammer drill to drill a pilot hole into the masonry, particularly concrete, and then use a screwdriver or power drill to screw the anchor into the hole. This makes their installation fairly easy and does not require very complex tools.

• Low maintenance

  Masonry screw anchors have a long lifespan, resisting pulling out, loosening, or rusting. This means they need little-to-no maintenance after being installed without replacement or repair over many years, making them ideal for fixed infrastructure for difficulty accessing areas.

Q&A

Q. 1. What kind of masonry screw anchor is best for fixing shelves on a concrete wall?

A. Concrete screws are the best anchor for this type of application. They can cut through concrete and provide a very tight grip, making them ideal for supporting heavy items, including shelves, on concrete walls.

Q.2 What are masonry screw anchors made of?

A.Masonry screw anchors are generally made of carbon steel for high tensile strength and durability. Heavily corroded environments call for stainless steel or galvanized varieties, which are also steel but with zinc or chromium coatings or addition of nickel to make them corrosion resistant.

Q.3 Are masonry screw anchors reusable?

A. Some masonry screw anchors like concrete screws are removable and reusable because they can be removed and bared back without damage to the screw or anchor point. However, expansion and sleeve anchors are not designed to be re-used due to permanent deformation on the anchor once used.

Q.4 What is the difference between masonry screw anchors and regular screws?

A.Masonry screw anchors have threads designed specifically for gripping the surface of masonry materials like concrete, brick, and stone. In comparison, regular screws have wood or metal board type threads not suitable for the strength required in masonry. This makes masonry anchors much stronger and carrying heavier loads than ordinary screws.