Simpson Split Drive Anchors
Published by Robert Carlisle on Aug 31st 2008
MSD/CSD/DSD Split Drive Anchors
Simpson Strong-Tie Anchor Systems® split drive anchors are a one piece anchor that has a mushroom head (MSD), countersunk head (CSD) or the duplex head (DSD) at one end. The opposite end of the head is split to allow for expansion once the split drive anchor is driven into the base material. The split drive anchor’s expansion mechanism compresses as it is driven into the base material. The compression exerts an outward force creating the holding values.
Simpson Strong-Tie Anchor Systems® Split Drive Anchors
Split drive anchors from Simpson Strong-Tie Anchor Systems® are designated by letters that refer to the head style of the split drive anchor: MSD represents mushroom head split drive, CSD represents countersunk split drive and the DSD represents duplex split drive.
MSD Split Drive Anchors
The MSD head is a low profile wide head to provide a superior bearing surface on the material being fastened. MSD split drive anchors are produced in the one diameter of 1/4” with six different lengths ranging from 1-1/2” to 4”. They are available in a zinc plating.
CSD Split Drive Anchors
The CSD is a flat countersunk head designed mainly for wood applications. The design allows the head of the split drive anchor to be countersunk into the wood and leaves the head flush with the surface of the wood. The CSD split drive anchor is available in only one diameter of 1/4” and is available in six diameters ranging from 1-1/2” long to 4” long. The various lengths come in a zinc plated version and the 3” and 4” are available in both zinc plating and mechanically galvanized.
DSD Split Drive Anchors
The DSD is a double headed split drive that, when set into the base material, can be removed with a claw hammer. It is designed for temporary applications like concrete forming. The sole diameter and length available in the DSD split drive anchor is 1/4” x 3”. The duplex split drive is zinc plated.
Split Drive Anchor Base Material
All of the different head styles split drive anchor should only be used in solid base materials such as concrete, stone, and grout filled block. The expansion of the split drive anchor is focused in one small area the anchor requires a solid base material to achieve holding values.
Hole Size for Split Drive Anchors
The hole to be drilled into the base material equals the diameter of the split drive anchor. All of the split drive anchors are 1/4”; therefore, a 1/4” hole must be drilled for the split drive anchor. The hole size is critical because the tolerance between the anchor and the hole must be very tight in order for the split drive anchor to work properly. To achieve the proper hole size tolerance, it is very important to use a hammer drill with a carbide bit that meets ANSI standards.
Hole Depth
The depth of the hole drilled should be slightly deeper than the split drive anchor will penetrate the base material. This extra space will allow an area for debris created during the installation process to fall into.
Depth of Embedment
The minimum embedment for all the split drive anchors is 1-1/4”. This means that the split drive anchor must penetrate the base material at least 1-1/4” to obtain proper holding values. Trying to embed the CSD and MSD split drive anchor deeper than 1-1/2” into the base material may cause the anchor to beend during the installation process.
Environments
Do not use the split drive anchor in environments that are wet or corrosive. The split drive anchor is a hardened fastener. Studies that have shown that hardened fasteners in these types of environments tend to have performance problems.
Split Drive Anchor Fixture Hole
The inherent design of the split drive anchor requires that the hole in the fixture being fastened be larger than the diameter of the hole drilled in the base material. For the MSD and CSD, a 3/8” hole is required if the fixture is of a harder material such as steel. For the DSD, it is recommended that a minimum of a 5/16” hole is in the fixture to be fastened.
MSD/CSD/DSD Product Information
Item # |
Diameter x Length |
Box Quantity |
Carton Quantity |
MSD25112 |
1/4” x 1-1/2” |
100 |
500 |
MSD25200 |
1/4” x 2” |
100 |
500 |
MSD25212 |
1/4” x 2-1/2” |
100 |
500 |
MSD25300 |
1/4” x 3” |
100 |
400 |
MSD25312 |
1/4” x 3-1/2” |
100 |
400 |
MSD25400 |
1/4” x 4” |
100 |
400 |
CSD25112 |
1/4” x 1-1/2” |
100 |
500 |
CSD25200 |
1/4” x 2” |
100 |
500 |
CSD25212 |
1/4” x 2-1/2” |
100 |
500 |
CSD25300 |
1/4” x 3” |
100 |
400 |
CSD25312 |
1/4” x 3-1/2” |
100 |
400 |
CSD25400 |
1/4” x 4” |
100 |
400 |
CSD25300MG |
1/4” x 3” |
100 |
400 |
CSD25400MG |
1/4” x 4” |
100 |
400 |
CSD25300 |
1/4” x 3” |
100 |
400 |
Split Drive Anchor – Installation
Loading capacity of the split drive anchor will be reduced if the hole in the base material is oversized. Embedding the MSD or CSD at greater depths than 1-1/2” may cause the split drive anchor to beend during the installation process.
1. With a 1/4” ANSI standard carbide bit, drill a hole in the base material using a hammer drill. The hole must be deep enough so that the split drive anchor will be embedded into the base material a minimum of 1-1/4” and there will be space for any debris to fall during the installation process.
2. With compressed air, clean the hole of all the base material dust. In overhead applications, cleaning out the hole is not necessary.
3. Position the hole in the fixture over the hole in the base material and insert split drive anchor through the fixture hole and into the hole in the base material. Make sure the hole in the fixture is 3/8” in diameter for the MSD and CSD, and 5/16” in diameter for the DSD.
4. With a hammer, drive the split drive anchor until the head of the anchor is flush with the surface of the fixture.