optimum tightening torque required for a bolt in rotating components and static components

[SMKRe]

optimum tightening torque required for bolt under static and dynamic conditions

Bolt size: M30,
Material: AISI4340 alloy steel
Grade (property class): 12.9
All Bolt threads to be lubricated with MoS2 grease during torque tightening.
Temperature variations will not be there.
Bolts are not subjected to any external loads.
If these bolts are used as foundation bolts of gear casing (static condition), What is the optimum tightening torque required?
suppose, if these bolts are used in flange coupling to connect the gear shaft with shaft of generator (dynamic condition). What is the optimum tightening torque required?

 

[hydtools]

Ted

 

[dvd]

https://www.appliedbolting.com/index-flange.php

Torque isn't tension video

 

[paulcook]

Wasn't aware that there are different torque recomendations based on static vs dynamic condition, but, I find these two references helpful for spec'ing torque values and determining load capacity:

Torque Chart

https://www.fastenal.com/content/me...nt-library/Torque-Tension Reference Guide.pdf

Technical Reference Guide

https://www-eng.lbl.gov/~shuman/NEX...e_vessels/FastenalTechnicalReferenceGuide.pdf

 

[SwinnyGG]

Wasn't aware that there are different torque recomendations based on static vs dynamic condition

There isn't

If you don't know what loads you need from your fasteners, you should be using the standard values. Unless you have a substrate issue, but that's more complicated.

 

[hydtools]

How would you define 'optimum'?

Ted

 

[Pud]

How would you define 'optimum'?

Way back when, 'optimum' was 5% into yield.

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