course provided an exceptional insight into bolting technology.
It covered a thorough range of topics from fastener design first
principles to failure analysis. From an engineer's perspective
it is an excellent course delivering a unique insight into a
subject that is an often misinterpreted basic engineering fundamental.
The engineers who attended from BAE Systems found the course
extremely valuable, gained a great deal of knowledge over the
2 days and ranked it as a superb, informative course."
This course is an introduction to bolting technology and includes
key information on the subject. A brochure is available on
this course and can be downloaded by clicking on the link
Training Course on Bolting Technology for Engineers and Designers
This training has been delivered world-wide
and receives very positive feedback:
Andy Lovatt, Mechanical Design Engineer, BAE Systems Land
"It is amazing how much from the course we are able to apply on a daily basis."
Jason M. Hall, Leader - Bolted Joints and Static Seals, Cummins Turbo Technologies
Matrix Engineering can deliver this course in North America, further information, including contact details are available on the Matrix website.
Training Course in North America on Bolting Technology for Engineers and Designers
The course content includes:
Introduction to Threaded Fasteners
Preload Variation in Threaded Fasteners
- Know the meaning of thread terminology.
- Learn when it is appropriate to use
a fine rather than a coarse thread.
- Be aware of the principal bolt and nut
strength property classes and how they should be specified.
- How to match the nut strength to that
of the bolt so that thread stripping problems are prevented.
- Find out why bolt tensile fracture is
preferable to the threads stripping.
- Learn what the proof load is and why
it is used.
- Be able to identify the meaning of the
markings on bolt heads and nuts.
- Learn about the thread stress area and
how it is derived and used.
- Be able to calculate the tensile strength
of a threaded fastener.
- Understand how a pre-tensioned bolted
joint sustains an applied load.
Galling of Threaded Fasteners
- Learn why there can be such a significant
variation in the preload (tension in the bolt) and the consequences
- How the torque is distributed between
the threads and the nut face when free spinning and torque
prevailing fasteners are used.
- Why preload is so crucial in a bolted
- How preload variation can be accounted
for at the design stage.
- The effect of the tightening method
on the preload variation sustained by a fastener.
- What is galling and what types of materials
tend to be affected?
- Examples of fastener threads that have
galled, sectioned and x-ray photos.
- Four ways that galling can be eliminated.
Methods of Tightening Threaded Fasteners
Have an understanding of the principles
behind each of the following tightening methods:
Failure Modes of Threaded Fasteners
- Torque controlled tightening.
- Torque-angle controlled tightening.
- Yield controlled tightening.
- Bolt stretch method.
- Heat tightening.
- The use of load indicating methods.
- The use of ultrasonics to determine
Vibration Loosening of Threaded Fasteners
- Learn the differences between a manufacturing
and design quality defect.
- Be able to identify whether a failure
is due to a fault in the design specification or is manufacturing
- Learn the 5 main design related failure
modes of threaded fasteners and bolted joints.
- Have knowledge of the critical importance
of a fastener's clamp force in ensuring a joint's structural
- Why the joint design normally prevents
- Learn about fatigue and where failures
normally occur on a threaded fastener.
- Why bearing stress can be crucial in
ensuring a reliable joint.
- Learn about the nature of internal and
external thread stripping failures.
Have an overview of the research completed
over the last 50 years into establishing the cause of self-loosening
of threaded fasteners.
Appreciate the forces that are acting on the threads that
tend to self loosen a fastener.
- Why fine threads
can resist loosening better than coarse threads. The inclined
- Learn about the work completed by Goodier
and Sweeney into loosening due to variable axial loading.
- The work completed by ESNA and the theory
of shock induced loosening and resonance within fasteners.
- The MIL-STD 1312-7 vibration test for
- Junker’s theory on self-loosening
of fasteners and why fasteners self-loosen.
- The Junkers/transverse vibration test
- The influence that vibration amplitude
has on the fastener self-loosening rate.
- Preload decay curves and the effectiveness
of various fastener types in resisting vibrational loosening.
- The findings of Haviland and Kerley
and how fasteners can come loose as a result of bending,
shock or impact and differential thermal expansion.
- Conclusions from the research and how
loosening can be prevented.
- What is meant by a tightening torque?
- Units used to measure torque.
- What are the consequences of not applying
sufficient torque to a bolt.
- How torque is absorbed by a nut/bolt
- The torque-tension graph.
- The relationship between the tightening
torque and the resulting bolt preload (tension).
- The factors which affect the torque-tension
- The nut factor method of determining
the correct tightening torque.
- Example calculation of how to determine
the correct tightening torque.
- Scatter in the bolt preload resulting
from friction variations.
- Determining the bolt preload (tension)
resulting from a tightening torque.
- Prevailing torque fasteners (such as
those containing a nylon insert) and how they affect the
torque distribution and the correct torque to use.
Load Sensing Fasteners
- The use of strain gauged bolts.
- The use of load cells.
- The use of Rotabolts™.
- The use of Smartbolts™.
- The use of direct tension indicators
(load indicating washers).
- Squirter™ direct tension indicators.
- Tension control bolts.
Hydraulic Tensioning of Threaded Fasteners
- The principles behind hydraulic tensioning.
- The number of tensioners that are used
to tighten a joint – 100%, 50%, 33% and 25% tensioning
- The effect of elastic recovery on the
tension induced into a bolt.
- The use of hydraulic nuts and the sequence
used to tighten them.
- The use of oil filled nuts.
- The use of rubber filled nuts.
- The problems of tightening multi-bolt
- Elastic interaction or bolt cross-talk.
- The use of a tightening sequence.
- The single pass tightening sequence.
- Tightening sequences for non-circular
- Tests completed to verify tightening
- The two pass tightening sequence.
- The use of multiple tightening tools.
- Bolt cross talk and hydraulic tensioning.
- Methods that can be used to check the
- The solder plug method.
- The use of pressure sensitive films.
- Establishing a tightening procedure.
- Examples of tightening sequences for
circular joints consisting from 4 to 32 bolts are given
in the handbook together with an example tightening procedure.
A training course handbook is provided that
contains background information to the material presented
in the course, together with appendices containing tables
of thread size details, fastener material strengths and a
glossary detailing the key terms used in bolting technology.
training course is also available now, online. Click for details.