Standard DTI FAQs
Inspection frequency using a feeler gage
Most inspectors check the DTI gap rigorously at the beginning of a project, then less frequently as the job progresses. Visual inspection of the residual DTI gap (that is, without a feeler gage) is very possible in many situations by experienced inspectors. However, as a specification requirement, we suggest a minimum of 10% or 2 bolts in each connection shall be inspected using a feeler gage of the correct thickness.
If entry of a feeler gage all the way into the bolt shank is allowed more than half way around the DTI circumference, the bolt is rejectable for installed tension at the discretion of the inspector. Torque wrench inspection shall not be used when DTI's are installed on the bolts.
