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TC bolt

Jayaprakash K

Structural
Mar 13, 2025
2
In the attached truss, there is a TC bolt connection for the aesthetic appearance of the mushroom head. I have a doubt about the bolt holes—are these standard holes in both connecting plates, or slotted holes in the column plate and standard holes in the truss plate? Please suggest a good idea.
 

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  • Truss frame.JPG
    Truss frame.JPG
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No need for a different hole layout for the TC bolts, just treat them like regular bolts.
 
For starters:
1) You should ask the design engineer for the bolt hole size & pattern.
2) Tension controlled (TC) bolts can only be turned via shear wrench on one side. If you have architectural requirements, verify which side the TC bolt head is on. Then verify that the erector can get a shear wrench on the bolt-assembly's nut. A good rule of thumb is 2" from bolt center to face of steel, but 1.75" is acceptable. 1-9/16" shown in the image would cause problems with the angles' outstanding leg (OSL).
3) The 4 bolts highlighted on the left side of the gusset connection are doing absolutely nothing...... except keeping a bolt manufacturer in business.
4) Also note, per AISC, you will need to have stitch plates at 1/3 points along the double angle braces, so the individual angles don't buckle before the brace assembly.
 
I would assume those bolts on the left bolt to something else not shown?
 

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