bodger
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| posted on 23/1/10 at 02:15 PM |
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Engineering Q - Thread pitch
Just wondering when it's considered necessary/appropriate to use a fine pitched bolt? Does it come down purely to the engineering calcs or is
there a best practise side too?
The prop to diff bolts on the Sierra are extra fine pitch so would like the other end to be bolted to the prop adapter (bec) with fine pitch. Not easy
to find M8 12.9 fine pitch bolts & nuts though.
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02GF74
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| posted on 23/1/10 at 03:09 PM |
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Good question.
googling around seems to indicate that a finer pitched thread is harder to undo due to more contact area.
A fine thread will have less depth as compared to a coarse thread, and consequently are easier to strip. A coarse thread is more resistant to
stripping but also less efficient in transmitting torque (turning) into thread tension. Generally, a fine pitch is easier to tighten in that tension
is achieved at lower torques.
Also of the threads aren't stipped., the bolts is stronger due to larger root diameter.
[Edited on 23/1/10 by 02GF74]
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britishtrident
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| posted on 23/1/10 at 05:15 PM |
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Recommend you use 5/16" UNF instead --- much easier to find.
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