Multi-Set is the brand name for ITW/ Red Head’s drop-in anchor that is designed for use in concrete. The multi-set drop-in RM drop-in anchor is a shell type anchor with internal threads made from steel with an expander cone inserted permanently inside the anchor body. The RM style Multi-Set drop-in anchor has a lip on the threaded end of the anchor to ensure flush and perpendicular embedment into concrete. Since the Multi-Set drop-in anchor is mostly used with threaded rod for hanging off ceilings, the flush mounting allows for consistent embedment depth and for the threaded rod to be perpendicular with the ceiling.
Multi-Set RM Drop-In Anchor
The Multi-Set drop-in anchor is manufactured from two different types of steel for different rust resistance for different environment applications. The zinc plated carbon steel RM drop-in anchor has low corrosion resistance and should be used in applications that are indoors or where moisture is not present. The 304 stainless steel RM drop-in anchor has excellent corrosion resistance in applications where moisture and some chemicals are present. The RM drop-in anchor made from 316 stainless steel has excellent corrosion resistance and can be used in and around moisture, submerged in salt water and in other environments where containing many other chemicals.
Multi-Set RM – Anchor Diameters
The RM Multi-Set drop-in anchor comes in five different diameters of 1/4”, 3/8”, 1/2”, 5/8”, and 3/4”, with each diameter available in one length. Unlike many other concrete fasteners, the Multi-Set RM drop-in anchor has only one length for each diameter. The anchor diameter of the Multi-Set RM drop-in anchor refers to the inside diameter or the diameter of the threaded rod or bolt that can be screwed into it. The threads of the Multi-Set RM drop-in anchor are all national coarse threads and extend into the anchor body about 1/3 of the length of the anchor.
Multi-Set RM – Drill Bit Diameters
The drill bit used for drilling the hole for a Multi-Set RM drop-in anchor should be carbide tipped, used in a hammer type drill and meet ANSI standard B212-15-1994 specifications. The designated size of the Multi-Set RM drop-in anchor refers to the inside diameter, the hole that must be drill is larger than the designated size of the anchor as it should be equal to the outside diameter of the anchor. A 1/4’ requires a 3/8” hole, 3/8” requires a 1/2” hole, 1/2” requires a 5/8”hole, 5/8” requires a 7/8” hole and a 3/4” requires a 1” hole.
Multi-Set RM – Embedment Depth
The RM Multi-Set drop-in anchor must be embedded into the concrete a minimum depth to provide minimum holding values. The length of the anchor is the minimum embedment that the anchor should be set into the concrete. Each diameter of anchor comes in only one length, and the entire length of the anchor must be embedded into the concrete to allow the lip of the RM Multi-Set anchor to be flush with the surface of the concrete.
Multi-Set RM Drop-in Anchor Installation
1. Drill a hole of the correct diameter into the concrete using a hammer type drill and a carbide bit that meets ANSI standards. Make sure that the diameter of the bit being used is the correct diameter for the RM Multi-Set drop-in anchor being installed.
2. Clean the hole of all dust and debris by using compressed air, vacuum or a wire brush.
3. Use a hammer to tap the RM anchor into the hole until the anchor lip is flush with the surface of the concrete.
4. Insert the setting tool into the RM anchor. Use a hammer to strike the setting tool until the lip of the setting tool meets the lip of the anchor, which will ensure that the anchor has been properly expanded.
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.