standard DTIs described above. Squirter brand DTIs from Applied Bolting Technology Products, LLC contain a small amount of material in the cavity of each protrusion. Such DTIs are mechanically and metallurgically identical to the standard DTIs described above, except that as the protrusions of these self-indicating DTIs collapse upon tightening, the cavity material is expelled to the outer diameter of the device, giving a visual indication of protrusion compression, i.e. bolt tension. While not approved by the ASTM or specifically mentioned within the RCSC specification, such DTIs are allowable because the RCSC specification requires all structural DTIs to conform to the ASTM F959 standard, whose reference documentation includes the ASME B18.2.6 standard. Since ASME B18.2.6 section 5.1 permits the inclusion of features to facilitate silicone-emitting DTIs, Squirter DTIs from Applied Bolting Technology Products, LLC are permissible and can be installed and inspected per the RCSC specification. Uses One of the more common uses of DTIs is in conjunction with EN 14399 pre-load bolt assemblies. References Sensors