BOLTING METHODS

DIRECT TENSION INDICATORS

DTI's are like little individual weigh scales, which measure the bolt tension developed during tightening, regardless of the torque resistance of the bolt. By far the simplest method, a DTI is put on one or the other end of all bolts, and after snugging the joint by partially (but not fully) compressing the DTI, all the DTI's are "crushed" to the point where a feeler gage cannot be inserted half way around, or to the point where the Squirter® DTI has squirted out silicone properly. DTI's are completely independent of the torque resistance of the bolt assembly, and because the compression of the DTI bumps can be seen by the eye, even without a feeler gage, bolt installers tend NOT to leave the bolts with insufficiently compressed DTI's.
When Using Squirter® DTIs, Installers don't miss any bolts. Inspection by using a feeler gage (on a sample of the bolts only) can be done by anyone at any time, when Standard DTI's or Squirter® DTI's are used. If the DTI is put on the nut end of the bolt, tightening can be done by one person because it is not necessary to hold the bolt roll.