WKTaylor
Well-known member
- Sep 24, 2001
- 4,119
Guys...
Many tech/design manuals fail to specify toqure-ranges [XXY--YYY inch pounds] for these type large diameter plain nuts, typically used to retain inner bearing races on a shaft [with locking washers or pins].
I have always been advised that "snug" [torque-wrench encounters sharp rise in torque when nut becomes firmly/properly seated]... is far better than over-torqued due to potential for anti-friction bearing binding.
When put into actual values, for-instance, an MS19068-40 or MS172242 nut [1.173-18] nut should be torqued 150--185-inch-# [Torque into this range, wait a few seconds for settling, back-off torque, then immediately final torque to low end-of range... and then advance nut until one or more lock-washer tabs [or pins] engage nut recesses or openings.
A table I developed looks like this [partial list of values]
0.9375-16 135--165-In#
0.9690-32 140--170-In#
1.0000-16 145--175-In#
1.1730-18 150--185-In#
1.2500-16 175--205-In#
1.3125-18 190--240-In#
1.3760-18 200--250-In#
1.4375-16 210--255-In#
1.5000-16 220--265-In#
Etc..
NOTE. One questionable reference I have actually increases these torques by 10X which seems absurd for bearing in mechanical assys.
This method assumes bearing inner-races are installed in the threaded shaft wet with grease; there is a slight grease lube on threads; and there is little/no run-on torque.
Comments? Your experiences?
Regards, Wil Taylor
Trust - But Verify!
We believe to be true what we prefer to be true.
For those who believe, no proof is required; for those who cannot believe, no proof is possible.
Unfortunately, in science what You 'believe' is irrelevant – "Orion"
Many tech/design manuals fail to specify toqure-ranges [XXY--YYY inch pounds] for these type large diameter plain nuts, typically used to retain inner bearing races on a shaft [with locking washers or pins].
I have always been advised that "snug" [torque-wrench encounters sharp rise in torque when nut becomes firmly/properly seated]... is far better than over-torqued due to potential for anti-friction bearing binding.
When put into actual values, for-instance, an MS19068-40 or MS172242 nut [1.173-18] nut should be torqued 150--185-inch-# [Torque into this range, wait a few seconds for settling, back-off torque, then immediately final torque to low end-of range... and then advance nut until one or more lock-washer tabs [or pins] engage nut recesses or openings.
A table I developed looks like this [partial list of values]
0.9375-16 135--165-In#
0.9690-32 140--170-In#
1.0000-16 145--175-In#
1.1730-18 150--185-In#
1.2500-16 175--205-In#
1.3125-18 190--240-In#
1.3760-18 200--250-In#
1.4375-16 210--255-In#
1.5000-16 220--265-In#
Etc..
NOTE. One questionable reference I have actually increases these torques by 10X which seems absurd for bearing in mechanical assys.
This method assumes bearing inner-races are installed in the threaded shaft wet with grease; there is a slight grease lube on threads; and there is little/no run-on torque.
Comments? Your experiences?
Regards, Wil Taylor
Trust - But Verify!
We believe to be true what we prefer to be true.
For those who believe, no proof is required; for those who cannot believe, no proof is possible.
Unfortunately, in science what You 'believe' is irrelevant – "Orion"