ESDU 14001:2012
$62.40
Applying, Measuring and Maintaining Pretension in Steel Bolts
Published By | Publication Date | Number of Pages |
ESDU | 2012-03 | 23 |
ESDU 14001 discusses factors affecting the tension in a bolt,
and indicates the methods by which a desired tension may be
obtained, with a comparison of their relative accuracy and cost.
Methods of measuring the bolt loads are also discussed. To
determine the bolt pretension achieved by application of a known
torque, the results of 1900 tests were analysed to yield curves for
both lubricated and unlubricated threads of BSF(BA) and Unified or
ISO metric forms. The test data related to nuts of mild and high
strength steel seated on mild or high strength steel or aluminium
alloy washers, and lubricants ranged from light oil to extreme
pressure greases. No significant trend with material or lubricant
was found. Techniques for applying a known torque are considered,
and their accuracy reviewed. Methods of locking the nut are
described, together with their advantages and disadvantages, and
include mechanical, frictional, adhesive or deformation
techniques.