There are a number of issues that need to be addressed when installing Tapcon® concrete screws. Trying to install Tapcons without consideration of these issues will decrease the chances of a successful fastening process.
Tapcons can be installed in concrete, brick, block and in the
mortar joints between the brick and block. The harder the base
material, the less embedment is required to attain sufficient holding
values. The minimum embedment for a Tapcon® concrete screw is 1” and
the maximum embedment is 1-3/4”. The holding values of the screw is
dependent on the quality of the base material. In applications where the
screw is being installed into the mortar joint, the holding values are
dependent on the quality and quantity of the mortar in the joint.
Diameter of Hole
Hole diameter is critical when installing Tapcons. The tolerance
between the hole diameter and the diameter of the Tapcon® screw being
used is very tight and any variations will effect the holding values.
Each diameter of concrete screw has a specific diameter carbide drill
bit that must be used for installation. The 3/16” diameter screw
requires a 5/32” hole and the 1/4” requires a 3/16” hole. The hole must
be drilled using a hammer drill with a carbide tipped bit
meeting ANSI standards. A bit that meets ANSI standards will insure
that the hole diameter will meet the requirements of the Tapcon®.
Depth of Hole
The depth of the hole that a Tapcon® concrete screw will be
installed into is critical. The hole must be drilled 1/4” deeper than
the screw will penetrate. This extra space at the bottom of the hole
allows for an area for the dust created during the tapping process to
fall without impacting installation. If enough space is not created
during the drilling process, the space may fill up with dust. The
concrete screw taps threads into the base material and the screw could
bottom out and prevent full installation. This situation may also lead
the concrete screw to become bound in the hole and unable to be removed
or inserted deeper.
Length of Tapcon® Concrete Screw
The overall length of the Tapcon® concrete screw chosen for any
particular application is very important. Different lengthconcrete
screws are used depending on the thickness of the material being
fastened. The screws require a minimum of 1” embedment and a maximum
embedment into the base material of 1-3/4”. To determine the minimum
length of concrete screw required for any job, add the thickness of the
material being fastened plus 1”. The maximum length that can be used is
determined by adding the thickness of the material plus 1-3/4”. Any
length that falls between the numbers obtained should work in the
Measurement of Tapcon® Concrete Screw Lengths
Flat head Tapcon® concrete screws are measured as an overall
length since they are countersunk, which means that the whole length of
the screw will be countersunk in the fixture and embedded into the base
material. Hex headed Tapcons are measured from under the head, because
the head will remain outside the fixture being fastened.
Tapcons come in two different head styles that are designed for
different types of applications. The full description of the
flat-headed screw is a flat countersunk phillips drive. The 3/16”
diameter flat head requires a #2 phillips driver and the 1/4” diameter
flat head requires a #3 phillips driver. The hex head is a hex washer
slotted head that is driven in by using a nut driver. The nut driver
for the 3/16”diameter Tapcon™ concrete screw needs to be 1/4”. For the
1/4” diameter concrete screw, it needs to be 5/16”.
Standard vs. Stainless Steel Concrete Screws
The standard blue Tapcon® is suitable for use in indoor
applications where moisture is not present. Standard blue Tapcons are
coated with a blue Climaseal® coating that provides good rust resistant.
The stainless steel screw is made from a 410 stainless steel and is
coated with a silver Climaseal® designed for applications where added
rust resistant is required.
Tapcon® Concrete Screw Installation Steps
1. Using a hammer drill and a carbide tipped masonry bit meeting
ANSI standards, drill a hole the correct diameter required for the
diameter of screw being installed. Make sure that the depth of the hole
will be a minimum of 1/2” deeper than the Tapcon® concrete screw will
if you still have any questions about Tapcons, take a look at these Tapcon® FAQs.
2. With a wire brush, compressed air or vacuum clean out the hole of all dust created during the drilling process.
3. Align the hole in the fixture over the hole in the base material.
4. Insert the concrete screw through hole in the fixture and into the hole in the base material.
5. Using a wrench or drill, rotate the screw until the head of the
concrete screw is tight against the surface of the fixture. Make sure
that the screw is not over-torqued as this may strip the threads in the
base material and cause it to spin in the hole.
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:
Mike Pistorino, Vice-President Operations
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.