Tightening a Threaded Bolt

[Michael GilliganParticipant @michaelgilligan61133]

Posted by William Harvey 1 on 02/09/2021 18:15:00:

[…]

Not sure?

On the side of the Tap it just says '3/8 NF 24'

.

Most likely then, that it is the ‘general purpose’ Class 2B

… and also likely that the original thread was Class 3B, to match a high-tensile bolt.

The tap would therefore take-out an extra ‘lick’ of metal … giving the result that you have observed.

MichaelG.

[William Harvey 1Participant @williamharvey1]

Posted by Michael Gilligan on 02/09/2021 20:20:25:

Posted by William Harvey 1 on 02/09/2021 18:15:00:

[…]

Not sure?

On the side of the Tap it just says '3/8 NF 24'

.

Most likely then, that it is the ‘general purpose’ Class 2B

… and also likely that the original thread was Class 3B, to match a high-tensile bolt.

The tap would therefore take-out an extra ‘lick’ of metal … giving the result that you have observed.

MichaelG.

So it now needs a Helicoil but to the correct thread for the HT bolt?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by William Harvey 1 on 02/09/2021 21:15:25:

[…]

So it now needs a Helicoil but to the correct thread for the HT bolt?

.

That would probably depend upon how “slight sloppiness” is quantified

… Sorry, I can’t advise

MichaelG.

[William Harvey 1Participant @williamharvey1]

So, I tested the bolt and torqued everything up to the recommended figure which I believe was 52Nm.

Torqued up fine, so I'll leave it at that.

I did not use the lock washer, but will do on the final build, also some Loctite 216.

[Michael GilliganParticipant @michaelgilligan61133]

MichaelG.

[Author]

Posts