A Step-By-Step Guide To Installing Drop-In Anchors

For anchoring things in concrete, drop-in anchors are specially designed as female concrete anchors. You drop the anchor into a pre-drilled hole in the concrete. To expand the anchor within the concrete hole, this device uses a setting tool, which it relies on for proper drop-in anchor installation. The following will examine the installation, uses, sizes, and holding strength of drop-in anchors.


As is commonly the case with female-type anchors, the drop-in anchor’s designated diameter refers to the anchor’s side diameter. Follow these directions for installation:

  • A hole will need to be drilled into the concrete. This is where the anchor will fit. The hole’s diameter will match the anchor’s outside diameter.
  • The length of the drop-in anchor is the minimum embedment for each anchor diameter.
  • To set the anchor, the bottom of the hole is required for this particular design of anchor.
  • With the open threaded end facing toward the surface, drop the anchor in the hole.
  • The proper setting tool should then be inserted.
  • To fully set the drop-in anchor, hit it with a hammer.


The following are some uses for a drop-in anchor:

  • If a bolt needs to be removed after being inserted, drop-in anchors are appropriate. They can be used in applications where a flush-mounted anchor is required.
  • To suspend fire sprinkler heads and pipes, for HVAC ductwork, and to suspend electrical cable trays, this type of anchor is used to insert a threaded rod.
  • Solid concrete is the only place where these types of anchors should be used.
  • Remember, in order for a drop-in anchor to set appropriately in concrete, a setting tool will be required.


Typically, drop-in anchors of every size are available in:

  • 316 stainless steel
  • 304 stainless steel
  • Standard zinc plating

Simpson Strong-Tie drop-in anchors, specifically, come in the following:

  • 316 stainless steel
  • 303 stainless steel
  • Standard carbon steel

Drop-in anchors are not manufactured:

  • In galvanized carbon steel
  • In diameters of 1 inch or 7/8 inch

Five diameters are available where drop-in anchors are concerned. One length applies to each diameter:

  • 3/4 inches
  • 5/8 inches
  • 1/2 inches
  • 3/8 inches
  • 1/4 inch

Holding Strength

To allow for greater contact with the concrete surface, this type of anchor has smooth sides. This helps provide holding values that are reliably consistent.

The depth of the embedment and the PSI of the concrete are two factors upon which a drop-in anchor’s holding value depends. Additional factors can include the anchor’s full expansion and if the concrete includes steel rebar.

Factory Direct Supply Has the Drop-In Anchors You Need

At Factory Direct Supply, we've got you covered when it comes to fasteners and anchors of all shapes, types, and sizes. Here's a sampling of some of our in-stock fastener/anchor products:

  • EZ anchors
  • Wedge anchors
  • Titen bolts
  • Retrofit bolts
  • Drop-in anchors

Take, for example, our Simpson Strong-Tie drop-in expansion anchor. It's suitable for suspending pipe supports, cable trays, conduits, suspended lighting, and fire sprinklers into concrete. Head over to FactoryDirectSupplyOnline.com today to browse our full range of products!