AutoTight® by Commins
Manufacturing, Inc.
The Continuous Rod Holdown System
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AutoTight® AT Take-Up Device

All AT Take-Up Devices Tested to ICC-ES AC316

The Shrinkage Problem: Wood dries and shrinks. This shrinkage results in loose non performing connections. The average wood floor system shrinkage is 1/2"! (The range is 1/4" to 3/4"). During an earthquake or extreme windstorm, the shearwall will lift before loads can be transferred into the structure. Substantial building damage will result before the wall begins to be laterally loaded. This movement will result in reduction in lateral wall capacity of 50% or more!

 The AT Auto Take-Up® keeps the wall tight by sensing the looseness and automatically expanding as the wood shrinks. Shearwall connections are kept tight and performing. The AT Auto Take-Up can accommodate over 1" of shrinkage or localized compression. The AT can also be stacked for 2” or more of take-up.

Testing:

The AT was tested to 104,683 pounds at failure and is load rated to 34,500 lbs.

Code Acceptance:

ICC ES ER-5889 per AC316; COLA RR 25480

Material:

Alloy Steel

Finish:

Yellow zinc chromate, moly di-sulfide dry lubricant.

Application:

The Commins AutoTight® Rod Holdown Systems, holdowns etc.
Installation Set-Nut-Activate
1.

Allow 4” of anchor bolt to project through the steel plate or holdown.
2.

Drop the AT device into the holdown - Arrow up.
3.

Place a steel washer on the AT (No lock washers!).
4. Install and tighten a nut on the AT. Tighten.
5. Activate. Remove and discard the activation screw.
The AT Auto Take-Up installs up to 10 times faster than the competition. Nothing installs faster!
US Patents 6,390,747 6,585,469 Other patents, foreign and domestic, pending
      
Model  ID OD Take-Up Allowable Average. Defl. @ Fits 
Number  (in.) (in.) Maximum (in.) Load    (lbs) Ultimate (lbs.)  Design Load Threaded Rod Diameter
AT 75 0.75 2.00 1.1 16,450 50,533 0.026” 5/8”- 3/4”
AT 75-2.5 0.75 2.00 2.5 15,183 54,724 0.020" 5/8" - 3/4"
AT 100 1.00 2.25 1.1 25,300 78,067 0.034” 7/8”- 1”
AT 125 1.25 2.75 1.1 34,500 104,683 0.025” 1-1/8”- 1-1/4”
Notes: AT may be stacked, Install per directions, keep clean and dry. Loads based on FS=3 on lowest of three tests.
Download - AutoTight® AT Product Description . pdf - (1 pages, 214k)

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Copyright 2005  Commins Manufacturing, Inc., Friday Harbor, WA 98250, Tel (360) 378-9484
 

AutoTight® Rod Holdown Systems and components are covered by one or more of the following U.S. Patents 6,390,747; 6,585,469; 6,625,945, other patents both foreign and domestic are pending.