Masonry screw anchors
are screws that tap threads in a pre-drilled hole in masonry. The
common name for these screws is Tapcon®. Masonry screws manufactured by ITW Redhead are made in America and sold by Concrete Fastening Systems, Inc. .
Masonry
Masonry refers to material used in the construction
of buildings made up of individual units bound together with mortar.
Masonry usually refers to brick or block, but can also include stone,
marble and granite.
Screw Anchors
Screw anchors are screws made from steel. They are
plated with hardened threads that allow the threads to tap hard,
abrasive material such as masonry. The screw anchors’ threads are
specially designed not only to tap the masonry but also to remove the
dust created during the tapping operation. The thread design of the
Tapcon® brand screw alternates high and low with notches cut into them
to allow removal of dust.
American Made Masonry Screw Anchors
Tapcon® brand masonry screw anchors are the original
masonry screw anchor developed and manufactured in the United States
since 1978. Many of the masonry screws sold are manufactured overseas
and do not meet the same standards as the Tapcon® brand masonry screw
anchor. As an indication of the importance of the blue Tapcon® masonry
screw, off brand masonry screws are manufactured to resemble them by
copying their blue color. The original and current Tapcon® masonry
screw anchors are blue with a special rust resistant coating called
Climaseal®.
Screw Diameter
The standard Tapcon® brand masonry screw anchor is
available in two diameters of a 3/16” and a 1/4”. Large Diameter Tapcon
masonry screw anchors are sold in 3/8”, 1/2”, 5/8, and 3/4” diameters.
Stainless Steel Tapcon® brand masonry screws are also available in a 3/16” and 1/4 ” diameter as well as the large diameter stainless steel in 3/8” and 1/2”diameters.
Hole Diameter
The diameter of the hole that needs to be drilled
into the masonry is smaller than the designated diameter of the masonry
screw anchor being installed. The 3/16” diameter requires a 5/32” hole,
the 1/4” diameter requires a 3/16” hole and the large diameter tapcon
with a 3/8” diameter requires a 5/16” hole, the 1/2” diameter requires a
7/16” hole, the 5/8” diameter requires a 1/2” hole and the 3/4”
diameter requires a 5/8” hole.
Hole Depth
When drilling a hole in the masonry to install
masonry screw anchors, the hole must be drilled a minimum of 1/4” deeper
than the masonry screw will penetrate the masonry. The extra depth
will allow space for any dust that is created during the tapping
operation to fall, which could negatively affect the installation
process.
Length of Screw
Adding the thickness of the material being fastened
plus the minimum embedment of 1” will determine the minimum length of
the masonry screw anchor used. The maximum length of masonry screw
anchor to be used is calculated by adding the maximum embedment of
1-3/4” plus the thickness of the fixture being fastened.
Masonry Screw Anchor Installation
The masonry screw anchor can be
installed in the masonry unit itself or the mortar joint between the
masonry units. The holding value of a masonry screw anchor is dependent
on the quality of the masonry unit as well as on the quality and
quantity of mortar in the mortar joint.
Step 1: Using the correct diameter
drill bit for the masonry screw being installed, drill a hole with a
hammer drill a minimum of 1/4” deeper than the depth the masonry screw
will penetrate the masonry.
Step 2: Position hole in fixture over
hole drilled in masonry and insert masonry screw thought the fixture
and into hole in the masonry.
Step 3: Turn the masonry screw clockwise until the masonry screw is flush and tight against the surface of the fixture being fastened.
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.
Article Written By:
Bob Carlisle, President of Concrete Fasteners
Concrete Fasteners, Inc. has over 40 years of experience selling concrete fasteners. We can ship out one box or a whole pallet of concrete anchors. Our products are of the highest quality... "your satisfaction is guaranteed". We ship all orders the same day the order is received.