Cap
Screws Internally Gauged 12-Point Strainsert SDH Series
Cap
Screws from Strainsert utilize an exclusive internal gauging
method to indicate bolt tension due to preload and subsequent
service loads with strain gauge accuracy.
Cap Screws from Strainsert are the first fasteners to
provide a means for accurate, independent inspection of
an assembled bolt for preload, thereby enhancing the structural
integrity and reliability of both the bolt and the assembly.
The gauging process consists of the installation of foil
type strain gauges bonded in a small hole drilled along
the longitudinal neutral axis of the bolt. This method
compares favorably in accuracy and stability with the
best external gauge installations, but it is vastly superior
to external installations in mechanical and environmental
ruggedness and miniaturization since the internal strain
gauge installation is self-protecting.
Neither the gauge nor the drilled hole reduce the allowable
bolt load in a Strainsert fastener. The gauge installation
will withstand and accurately indicate the full allowable
load of the highest strength bolts available. Hole depth
is confined to the grip length of the bolt and the hole
diameter is controlled so that the bolt cross-section
through the threads is smaller than the section through
the shank with the gauge hole.
To Measure accurate preload, service load and overload
of bolted assemblies.
For Maximum uniformity, efficiency and reliability
in bolted assemblies.
For Effective research, testing and manufacture
of bolted assemblies.
Cap
Screws from Strainsert utilize an exclusive internal gauging
method to indicate bolt tension due to preload and subsequent
service loads with strain gauge accuracy. 
