A winch is a stationary mechanical device which is either hand
powered or machine powered and is ued to wind up (pull) or wind out (let
out) a cable or rope. In order to work properly, a winch must be
fastened down securely to a base material. If a winch needs to be
fastened to concrete, then it is essential that the correct concrete anchor
is used. Large winches need to be fastened to the concrete with the use
of a cast-in-place anchor or epoxy. Smaller winches can be fastened to
the concrete by using mechanical type concrete fasteners such as wedge
anchors. This article describes the process of fastening smaller winches
to concrete using mechanical type concrete anchors.
A winch that is designed to be fastened to concrete will come
with mounting holes or attachable brackets with mounting holes. The size
of these holes will determine the diameter of anchors that need to be
used. There are two types of concrete anchors that can be used for
fastening a winch: a male type anchor or a femal type anchor. The male
type anchor will allow the fixture to be in place and the anchor
inserted through it. Female type concrete anchors will require the hole
to be spotted, the fixture removed, the anchor set in place, the fixture
set back over the anchor and a bolt inserted through the fixture into
the concrete anchor. It is important to follow the specifications stated
by the manufacturer of the winch being fastened. This will help you
select the type of anchor to be used.
Male Type Concrete Fasteners
Male type concrete fasteners allow for drilling and placement of
an anchor while the fixture remains in place. It is very important to
check that the anchor will fit through the mounting holes in the fixture
and/or bracket. A designated diameter is larger than true hole size
when using concrete fasteners. For example, a 1/2" wedge anchor requires
a 9/16" hole in the fixture.
The following chart provides more detail about concrete anchor diameters and corresponding mounting hole diameters:
| 1/4" |
5/16" |
| 5/16" |
3/8" |
| 3/8" |
7/16" |
| 1/2" |
9/16" |
| 5/8" |
11/16" |
| 3/4" |
7/8" |
| 7/8" |
1" |
| 1" |
1-1/8" |
| 1-1/4" |
1-3/8" |
Strike Anchors
Strike anchors
are male type concrete anchors designed for use in solid concrete. The
strike anchor utilizes a hardened drive pin to expand the body of the
anchor against the concrete. Strike anchors are made from carbon steel
material and are plated with yellow zinc. Anchor size is equal to hole
size. A hammer is all that is needed to set the anchor. A design feature
that makes the strike anchor different from the wedge anchor is that
the nut is not used to set the anchor. This design allows the strike
anchor to be preset at a specific depth. This provides uniform
consistency of the anchor protuding above the fixture.
Wedge Anchors
Wedge anchors
are the most commonly used concrete anchors for this type of
application. They are readily available, easy to use and have the most
consistent holding values in concrete. Wedge anchors should be used in
concrete only and should never be used in other base materials. The
wedge anchor is a steel stud with threads on one end and a clip on the
other. Wedge anchors are manufactured from carbon steel and is zinc
plated or from stainless or carbon steel that is hot-dipped galvanized.
The winch must be set in place and a hole drilled in the concrete and
through the mounting holes. The wedge anchor is then inserted through
the mounting holes and into the concrete. The nut is then turned 3-4
times to set the anchor in place.
Female Type Concrete Fasteners
Female type concrete anchors require that a bigger hole than the
bolt that is placed into it. For example, if the mounting hole is 1/2"
diameter and a 1/2" bolt will be used, then a 1/2" female anchor will be
used. Furthermore, a 1/2" female anchor will require a 5/8" to3/4" hole
to be drilled in the concrete. This will require the winch to be set in
place, the concrete marked where the mounting holes are and the winch
to be moved so that the holes are be drilled in the concrete. The anchor
is then set in place, the winch moved back over the anchors, the
mounting holes lined up with the anchor and the bolt to be inserted
through the holes into the anchor. Female type anchors do not require a
shear rating because the shear value is dependent on the grade of steel
that the bolt is made from. When working with female concrete anchors,
the length of the bolt required can be determined by adding the
thickness of the material to the thickness of the nut & washer plus
the length of the anchor.
Drop-in Anchors
Drop in anchors
have the most consistent holding values of any female type concrete
anchors. Drop in anchors are available in zinc plated carbon steel and
stainless steel in the following diameters: 1/4", 3/8", 1/2", 5/8" and
3/4". Each diameter comes in one length and a specific setting toll if
required for each diameter. The internal threads of these anchors are
coase and extend approximately half the length of the drop in anchor. An
internal plug is held in place and is designed in a cone like shape
that when pushed into the anchor with the setting tool, expands the
working end of the drop in anchor against the wall of the hole in the
concrete.
Below is more information about drop-in anchors:
| 1/4" -20 |
1/4" |
3/8" |
1/4" |
| 3/8" -16 |
3/8" |
1/2" |
3/8" |
| 1/2" -13 |
1/2" |
5/8" |
1/2" |
| 5/8" -11 |
5/8" |
3/4" |
5/8" |
| 3/4" -10 |
3/4" |
1" |
3/4" |
Lag Shield Anchors
Lag shield anchors
are versatile and are available in two different lengths: short for use
in hard base materials and long for use in suspect base material. Lag
shields made from rust resistant zinc and are available in 6 different
diameters: 1/4", 5/16", 3/8", 1/2", 5/8", and 3/4". The lag shield
requires a lag-threaded screw to be used with the anchor. The lag shield
is designed to expand as the screw is inserted into it without any use
of a setting tool.
Single and Double Expansion Anchors
Both single and double expansion anchors are made from rust
resistant zinc material. In single expansion anchors, a single internal
nut this is pulled up through the anchor to expand the body of the
anchor. The double expansion anchor
has double expanders consisting of a single nut on one end and an
expander sleeve on the other. As the nut is pulled up into the anchor
bodies, the expander sleeve moves the opposite way and expands the
anchor the entire length of the body. Both anchors are versatile since
they can be used in a variety of base materials including concrete,
brick and block. Single expansion anchors
work more efficiently in harder base material and the double expansion
anchor derives better holding values in suspect base material. Six
diameters are available including: 1/4", 5/16", 3/8", 1/2", 5/8", and
3/4".
Fastening a winch to concrete or any other base material (such as
brick or block) is an application that requires the use of concrete
anchors. Depending on the specifics of your application, there are a
variety of fasteners that will work in this specific type of project.
Both male and female type anchors can be used to fasten a winch to
concrete.
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.