Material and Coating
Each Tapper® by Powers is manufactured from carbon steel and is coated with a blue Perma-Seal coating for rust resistance.
To locate information about the diameter of the concrete screw anchor, refer to the first number in the product description. As an example, in the description of 1/4” x 2-3/4” the first number of 1/4” refers to the diameter of the screw.
The second number in the product description refers to the length of the concrete screw anchor. For example, in the description of 3/16” x 3-1/4”, the 3-1/4 refers to the length of the screw. Hex headed Tappers® are measured from underneath the head, and the flat countersunk Tappers® are measured as an overall length including the head.
The Tapper® masonry anchor taps threads into a predrilled hole in the masonry base material. A 3/16” Tapper® requires a 5/32” hole while the 1/4” Tapper® requires a 3/16” hole.
The bit must be a carbide tipped masonry bit that meets ANSI standards, and must be used in a hammer drill that is set in the hammer and rotation mode for drilling the hole in the masonry material.
Depth of Hole
The hole in the base material must be drilled a minimum of 1/4” deeper than the embedment of the Tapper® masonry screw. For example, if the screw will be embedded into the masonry 1-1/4” then the hole must be a minimum of 1-1/2” deep. This extra space allows for any dust created during installation to fall out of the way.
To ensure minimum holding strength in the masonry material, all Tapper® masonry screws must be embedded into the masonry material a minimum of 1”.
The maximum embedment for any Tapper® ranges from 1-3/4” to 2” depending on the hardness and abrasiveness of the masonry material that the screw is installed.
The maximum thickness of the fixture for any Tapper® is determined by subtracting the minimum embedment of 1” from the length of the screw being installed.
Fixture Clearance Hole
The threads of the 3/16” diameter Tapper® measures 3/16’ with 11 threads per inch, and is referred to as 11-16 threads. The 1/4” Tapper® has 15 threads per inch and is referred to as 1/4 - 15 threads.
Head Height and Width
The height of the head on a 3/16” hex headed Tapper® measures 7/16” and is 1/4” in diameter; the height of the flat head on the 3/16” is 9/64” and measures 3/8” across. The 1/4” hex-headed Tapper® head height is 7/64” and is 5/16” diameter; the flat head is 3/16” and measures 1/2” across.
Washer O.D. and Thickness
For the 3/16” diameter hex washer head Tapper®, the outside diameter of the washer is equal to 11/32” and has a thickness of 1/32”. The outside diameter for the 1/4” Tapper® is 13/32” and is 1/32” thick.
The driver required for the 3/16” Tapper® hex head is 1/4” and a # 2 phillips driver is needed for the flat head. The 1/4” Tapper® needs a 5/16” driver and uses a #3 phillips driver for the flat head.
Each Tapper® masonry screw is packaged 100 pieces per box with one correct diameter and length carbide tipped bit included. Each carton contains 5 boxes or 500 pieces.
Allowable Load Capacities
The allowable load capacity is calculated using a safety factor of 4. Linear interpolation may be used and the critical minimum spacing and edge distance, as well as reduction factor, are listed in the design criteria section at Installation.
Using the correct diameter ANSI standard carbide tipped bit for the Tapper® being installed, drill a hole in the masonry a minimum of 1/4” deeper than the required embedment...
- Blow the hole clean of all dust and other material
- Insert the head of the screw into the appropriate driver and set the drill to rotation only.
- Insert the point of the Tapper® screw through the hole in the fixture and into the predrilled hole in the base material.
- Drive the Tapper® in one steady continuous motion until the head is tight against the surface of the fixture.
- Make sure the masonry screw does not spin in the hole.
Please remember with all fastening jobs to keep safety in mind. Always follow safety instructions on all tools, and refer to manufacturer's installation instructions when available and always remember to wear safety goggles!
Article written by: Bob Carlisle, President Concrete Fastening Systems, Inc