ThunderDrop® - 1/4" American Made Drop-In Anchor (three zero three) 303 Stainless Steel
The 1/4" American Made Drop-In Anchor (three zero three) 303 Stainless Steel is designed for outdoor, wet applications. A setting tool is required to set each anchor in the concrete. Buy direct to save. All orders ship immediately with no charge for freight.
- Bit Size 3/8"
- Minimum embedment 1"
- For use in solid concrete, not to be used in brick or block
- For wet, outdoor environments
- Meets BAA requirements
- One length per diameter
- Internal threads are national coarse
- Setting tools sold separately
- All orders over $25.00 ship freight free
|Thread Type||1/4" - 20|
|2000 PSI Concrete - Pull-Out (lbs.) *||939|
|Material||303 Stainless Steel|
|Minimum Edge Distance||1-7/8"|
|Minimum Fixture Hole Diameter (In Place)||7/16"|
|Minimum Fixture Hole Diameter (Hole Spotted)||1/4"|
|Maximum Torque||5 ft./lbs.|
|Inside Anchor Diameter-Bolt Diameter||1/4"|
|Outside Anchor Diameter||3/8"|
|Internal Thread Length||7/16"|
|Length Measurement||End to End|
|Bolt Length||Fixture Thickness + Embedment Depth|
The anchor is made from 303 Stainless Steel and meets the Buy America Act (BAA). This anchor is designed for use in Concrete only, and should never be used in block or brick base material.
The anchor is designed for use in a Wet environment.
Hole Diameter/Bit Diameter
The anchor requires a 3/8" hole to be drilled in the base material (Concrete only). The hole should be drilled with carbide tipped bit that meets ANSI standards and used in a hammer drill.
The designated size of the anchor refers to the inside diameter 1/4" of the anchor or the diameter of the threaded rod or bolt that can be inserted into it.
Diameter of Anchor
The diameter of the anchor is 1/4".
The length of the anchor is 1"
The threads on the anchor are internal threads that measures 1/4" with 20 threads per inch, commonly referred to as 1/4"-20 .
The length of the threads on the anchor is 7/16" in length.
Each anchor must be set in the concrete with a specific setting tool. The anchor is set using the 1/4" setting tool which is sold separately.
The anchor is packaged with 100 pieces per box and does not come with a setting tool.
The minimum anchor embedment into the concrete is 1". Therefore, the anchor must be installed so that a minimum of 1" of the anchor is embedded into the concrete.
Depth of Hole
The hole in the concrete can be deeper than the minimum embedment depth for the anchor. Deeper embedment will usually result in better holding strength.
Fixture Hole Diameter
The hole in the fixture or material being fastened must be larger than the designated diameter of the anchor. The 1/4" diameter anchor requires the hole in the fixture to be 7/16".
The maximum torque that can be applied to the anchor once installed is 5 ft./lbs.
Spacing between Anchors
Each anchor must be spaced a minimum distance of 3-3/4" from each other when measured center to center.
It is very important not to install the anchor any closer than 1-7/8" from an unsupported edge of the concrete.
When a bolt is used in conjunction with the anchor, the length of the bolt needed is determined by considering these factors:
- Flush With Concrete - when the anchor is set flush with the surface of the concrete, add the thickness of the material being fastened to the thread length of 7/16", and then add the space for any washers used.
Below Surface of Concrete - add the depth below the surface of the concrete to the thickness of the material being fastened, then add the space for the washer, and, finally, add 7/16" for the thread engagement.
Holding Values - Ultimate Load Values in 2000 PSI Concrete
1/4" x 1"
- Drill a 3/8" hole into the concrete using a carbide-tipped bit that meets ANSI Standards B212.15.
- The depth of the hole can be deeper or equal to the minimum embedment depth of 1" which is equal to the length of the anchor .
- Clean the hole with a wire brush, vacuum, compressed air, or a blow-out bulb.
- Insert the anchor into the hole with the open threaded end facing up.
- Take the correct 1/4" American Made Drop-In Anchor (three zero three) 303 Stainless Steel setting tool and insert the smaller diameter end into the threaded portion of the 1/4" American Made Drop-In Anchor (three zero three) 303 Stainless Steel.
- Strike the end of the setting tool with a hammer until the anchor is fully set.
- The 1/4" American Made Drop-In Anchor (three zero three) 303 Stainless Steel is now set. A 1/4" diameter threaded rod or a bolt can be inserted into it with a maximum torque of 5 ft./lbs.
- Always use proper personal protective equipment per manufacturer's and OSHA instructions.