The Hilti HDI-P drop in anchor is a female anchor sold by Hilti, Inc. and is designed for use in concrete base material. It should not be used in applications where the base material is brick or block. The HDI-P is manufactured from mild carbon steel and protected from corrosion with zinc plating in accordance with ASTM B633, SC1, Type III. The Hilti drop-in anchor HDI-P is an expansion anchor that has an internal thread for use in solid and hollow concrete and is designed for flush mounting applications. This anchor is unique because it is designed for use in post-tension concrete construction jobs such as parking garages or high rise buildings where post tension cables are used to strengthen the concrete. These post tension cables run through the concrete and must not be compromised in any way.
The HDI-P anchor allows for a shallow embedment of 3/4", meeting the embedment depth requirements for post-tension concrete. This anchor has a lip on the open threaded end that provides consistent rod alignment and depth of embedment. This anchor requires the use of a setting tool to expand the anchor. This setting tool is designed to leave a mark on the lip of the anchor to signal that it is properly set. This allows for verification and inspection after installation to ensure that the anchor has been properly expanded. The HDI-P is available in the 3/8" diameter only. The 3/8" measurement refers to the inside diameter and requires a 1/2" hole to be drilled. Each anchor can hold about 380 lbs. in tension when placed in 4,000 psi concrete and can hold about 420 lbs. of tension when placed in hollow core concrete.
There are other female concrete anchors that are equivalent to the Hilti HDI-P anchor in holding values and material specifications. These other anchors have basically the same specifications and are installed the same. The HDI-P anchor is Hilti's brand name for its drop-in anchor and other companies have their own brand names for this type of anchor as well. Concrete Fasteners, inc. is the only company that labels its drop-in anchor by its generic name (drop-in anchor). The biggest difference when comparing drop-in anchors will be the price. Concrete Fasteners, Inc. has the lowest price on the internet.
1. Set the depth of the anchor on the drill using the depth gauge or by placing a piece of tape on the drill bit.
2. Drill the hole using a hammer drill and a carbide bit that meets the requirements of the HDI-P.
3. Clean out the hole of any debris creating during the drilling process.
4. Drop the anchor into the hole with the threaded portion of the anchor facing upwards.
5. Insert the setting tool into the internal threaded part of the anchor. Using a hammer, strike the setting tool until the lip of the setting tool meets the lip of the HDI-P anchor.
The Hilti HDI-P anchor can be used in applications when fastening to concrete only. These anchors are only available in one size- 3/8" diameter. It is important to install these anchors properly to achieve maximum holding values and correct embedment.
As with any anchoring project, it is important to keep safety in mind and follow instructions carefully. Always remember to wear safety goggles, handle all tools with extra care and follow all technical specifications. This article is meant to serve only as a basic explanation of concrete fasteners. Always refer to manufacturer's instructions or consult a contracting expert during any anchoring project.