The coil threaded drop-in anchor (DIAC) brand is a drop-in anchor
manufactured and sold by Simpson Strong-Tie Anchor Systems that has
internal coil threads instead of the national coarse threads in the
standard drop-in anchor. Coil threads are large threads that provide
quick threading and are most often found used in concrete forms for
bridge construction. Concrete Fasteners, Inc., like most companies
that sell standard drop-in anchors, has available a coil threaded
version of the drop-in anchor. The coil threaded drop-in anchor is designed for use in solid concrete only.
Material Specifications
The coil threaded drop-in anchor is not manufactured from any type
of stainless steel other than the standard zinc plated carbon steel.
The steel that is used for the body of the coil threaded drop-in anchor
has a minimum tensile strength of 70,000 psi and the expansion plug has a
minimum tensile strength of 50,000 psi.
Coil Threaded Drop-In Anchor Criteria for Testing
Coil threaded drop-in anchors have been tested in accordance with
the ICC-ES’s criteria for expansion anchors, for tension and shear loads
in wind loading and seismic, minimum spacing, edge distance as well as
combination loads.
Codes and Approvals
The coil threaded drop-in anchors meet the following codes or have approvals:
City of Los Angles RR24682
U.L. # Ex3605
Factory Mutual 3017082
Coil threaded drop-in anchors meet Federal Specifications A-A-55614, Type 1.
Available Diameters
The coil threaded drop-in anchor come in only two diameters of
1/2” and 3/4”. They are designed to accept either 1/2” or 3/4” coil
threaded rod or bolts.
Available Lengths
Each diameter of coil threaded drop-in anchor comes in one length.
The length of the anchor is standard and the same as the standard and
lipped drop-in anchors. The length of the anchor is equal to the
minimum embedment that the coil-threaded anchor should be place in the
concrete. The 1/2” coil threaded drop-in anchor is 2” long and the 3/4”
coil threaded drop-in anchor is 3-1/8” long.
Coil Threaded Drop-In anchor Threads
The internal threads of the coil threaded drop-in anchor are large
compared to the standard national coarse threads in the standard
drop-in anchor. The 1/2” coil threaded drop-in anchor has 6 threads per
inch and the 3/4” coil threaded drop-in anchor has 5 threads per inch.
The internal threads of the anchor determine the designated diameter of
the coil threaded drop-in anchor.
Diameter of Hole
The size of the hole to be drilled into the concrete is equal to
the outside diameter of the coil threaded drop-in anchor. Since the
designated size of the coil drop-in anchor is equal to the inside
diameter coil threads, the outside diameter is larger than the
designated diameter. The 1/2” coil threaded drop-in anchor’s outside
diameter is 5/8” and the 3/4” coil threaded drop-in anchor’s outside
diameter is 1”.
Minimum Embedment Depth
The minimum embedment in the concrete for the coil threaded
drop-in anchor is equal to the anchor length of the coil threaded
drop-in anchor being installed. The minimum embedment is equal to the
anchor length. Each coil threaded drop-in anchor must be placed in the
concrete so that the open threaded end is flush with the surface of the
concrete. Both diameters of anchors can be embedded deeper if needed.
Setting Tool
The coil threaded drop-in anchor is an internally set type of
concrete anchor that requires a setting tool to be used to expand the
anchor. Each diameter of coil threaded drop-in anchor has a specific
setting tool that must be used to insure the anchor is properly expanded
and set in the concrete. The 1/2” coil threaded drop-in uses the 1/2”
setting tool and the 3/4” coil threaded drop-in uses the 3/4” setting
tool. The setting tools used for the coil threaded rod drop-in anchors
are the same tool used for setting the standard and lipped drop-in
anchors of the same diameter.
Coil Threaded Drop-In Anchor Installation
1. A hammer drill must be used to drill the hole in the concrete
for the coil threaded drop-in anchor. Using the correct diameter
carbide tipped drill bit that meets ANSI standards, drill the hole into
the concrete 1/8” deeper than the coil threaded drop-in anchor will be
embedded. Make sure that the hole is not oversized because an oversized
hole will make it difficult to set the coil threaded drop-in anchor and
will reduce the holding values.
2. Compressed air can be used to clean the hole of all debris and concrete dust.
3. Insert coil threaded drop-in anchor into the hole in the
concrete until the open end of the anchor is flush with the surface.
4. Place setting tool into the open internally threaded part of
the coil drop-in anchor. Using a hammer, hit the end of the setting
tool until the lip of the anchor meets the lip of the setting tool to
insure that the coil threaded drop-in anchor is fully expanded.
Coil Threaded Drop-in Anchor Product Information
|
Coil Drop-in Part Number
|
Internal Diameter Of Anchor
|
Drill Bit Diameter
|
Length Of Anchor Body
|
Quanity Per Box
|
|
DIA50C
|
1/2”
|
5/8”
|
2”
|
50
|
|
DIA75C
|
3/4”
|
1”
|
3-1/8”
|
20
|
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.