Anchor Bolts Resource


For Concrete Installations Use Drop-In Anchors

Drop-in anchors are inserted into concrete so that brackets, railings, pipes, and other hardware can be attached. They are female components with a threaded interior and smooth exterior. 

Drop-in anchors are meant to be used exclusively in concrete. They are placed in pre-drilled holes, which are created with a power or hammer drill. The anchors are then placed and set using a setting tool. The tool expands the lower portion of the anchor, which fixes it in place as part of a permanent installation. Once installed, an anchor bolt, threaded rod, or other fasteners can be tightened in place. 

These anchors are made from materials including carbon steel and stainless steel. They can also be zinc-coated to enhance outer resistance. Among key specs to consider when choosing these anchors are the thread UNC and the diameter. 1/2”, 1/4” and 5/8” drop in-anchors are some of the most in-demand varieties. 

Drop-in anchors are meant to be a permanent part of an installation. It’s not possible to remove them unless the concrete in which they are embedded is also cleared. They can be filled in if the anchors are installed deep enough and concrete can be patched or poured over them.

How Are Drop-in Anchors Installed?

Drop-in anchors are installed by creating pre-drilled holes in concrete. The anchors are put in place using a hammer. Then, a setting tool is required to make the lower portion of the anchor expand. This expansion permanently affixes the anchor in the concrete and allows for a threaded fastener, such as a bolt or rod, to be tightened in place and hold hardware such as railings and brackets to the concrete.  

Can You Use Drop-In Anchors In Brick?

Drop-in anchors are not intended for use in brick or similar masonry. They are meant to be installed in concrete. They can be used in some thicker stone-based foundations. When anchors must be installed into brick, lag shields and expansion anchors may be a more reliable option. 

How Do I Get Rid Of Drop-In Anchors?

Drop-in anchors are meant to be permanently installed. They only way to remove them is to remove the portion of the concrete in which they are installed. Exposed parts of the anchor can be sawed or ground off using the appropriate tools. If the anchors are recessed far enough into the concrete, the new material can be poured or patched over the anchor. 

Do Concrete Screws Need Drop-In Anchors?

Concrete screws do not require drop-in anchors. They can be installed directly into the concrete. Drop-in anchors and other types of anchors are used where bolts and rods are needed to hold a rail, bracket, or similar piece of hardware directly in the concrete.

What Type Of Drill Bit Is Used For 5/8 Drop-In Anchors?

A 5/8” drop-in anchor can be installed into a minimum of 2 1/2” of concrete using a 7/8” drill bit. The bit size for creating the pre-drilled holes is slightly larger than the diameter of the drop-in anchor. The anchor will then expand to the width of the hole once a setting tool is used to complete the installation.