Standard DTI FAQs
Condition of the bolt threads
- You are compressing the DTI's OK but you think you are "overtensioning"
or 'overtightening' your bolts. What should you do?
- You try your best but it appears too difficult to properly compress
the DTI bumps, even though the ironworkers sit on the bolts for 20,
30, or more seconds. See bolt thread damaged
- You break some bolts before their DTI's have been compressed sufficiently.
See breaking bolts
- Do you have some evidence of stripped bolts? See Stripping of Bolts
You are compressing the DTI's OK but you think you are "overtensioning" or 'overtightening' your bolts. What should you do?
There is no such thing as an ASTM A325 or ASTM A490 "overtensioned" or "overtightened" bolt, unless it is broken. The installation specifications all require bolts to be tensioned OVER a minimum value, (see bolt tension chart), and do not specify a maximum. A good way to check this is to tighten a bolt and DTI to the point where you feel that perhaps it has been overtensioned, whatever that means, say to the point where the DTI has been completely compressed so there is no visible gap remaining. Remove the bolt from the hole, and examine the threads. They should be intact, without sign of any thread distress or stripping. The bolt can be "necked" a little, and this is OK. It should be possible to rethread on the nut to the point where it had been before disassembly, but not necessarily to the root of the thread.
