Confast Drop-In Anchors Now Available

Confast drop-in anchors are now available for suspending electrical cable trays, HVAC ductwork and fire sprinkler pipe, heads and more.

  • Drop-In anchors should only be used in solid concrete.
  • Their main use is to insert threaded rod to suspend electrical cable trays, HVAC ductwork and fire sprinkler pipe and heads.
  • They can be used in applications that require a flush mounted anchor and when a bolt needs to be inserted and removed.
  • A setting tool is required to set the anchor in the concrete.
Technical Specifications

There are numerous technical specifications that must be considered when using Concrete Drop-in Anchors. Considerations include diameter and material type, internal thread length, minimum edge distance and required hole size.

The Concrete Drop-in Anchor is a great fastener option when working with flush mounting applications. The size of the Drop-in Anchor refers to the diameter of the standard UNC threaded rod or bolt to be used with this fastener. Once all these factors have been determined, you can find the expected holding values in the technical information below.


When setting the anchor flush with the base material: To determine the minimum bolt length required, add the internal thread length of the anchor, plus the thickness of the material to be fastened, plus the thickness of any washer to be used.

When setting the anchor deeper into the concrete:

Determine the minimum bolt length above and add the additional depth to the minimum anchor length.

  • As with all female type anchors, the designated diameter of the Drop-In anchor refers to the side diameter of the anchor.
  • The outside diameter of the anchor is equal to the hole diameter required to be drilled in the concrete.
  • Minimum embedment for each diameter of Drop-In anchor is the length of the anchor.
  • The Drop-In Anchor requires the bottom of the hole to set the anchor.
  • First, drop the anchor in the hole with the threaded open end up towards the surface, then insert proper setting tool and hit with a hammer until the Drop-In anchor is fully set.
  • The holding values of the Drop-In anchor are mainly dependent on the PSI of the concrete and on the depth of embedment. Other factors include if steel rebar is in the concrete and on the full expansion of the Drop-In anchor.
  • The Drop-In anchor has sides that are smooth to allow for more surface area to be in contact with the concrete, thereby providing consistent holding values.
  • Drop-In anchor are manufactured in five diameters, each diameter has one length.
  • The Drop-In anchor is not manufactured in diameters of 7/8″ or 1″.
  • Every size of the Drop-In anchor is available in standard zinc plating, 304 stainless steel and 316 stainless steel.
  • No diameter of the Drop-In anchor comes in a galvanized carbon steel.
About Concrete Fastening Systems, Inc.

Concrete Fastening Systems, Inc. has sold concrete fasteners for over 30 years from a fully stocked warehouse in Cleveland, Ohio. Free, same-day shipping in every length and diameter is available by ordering at, followed by product delivery within 1-3 days.


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