turbogrill Posted February 25, 2018 Report Share Posted February 25, 2018 Hi I bought a exhaust stud kit. It comes with pinch nuts. These nuts requires force to put them on. Is This expected? Link to comment Share on other sites More sharing options...
Ian Moone Posted February 25, 2018 Report Share Posted February 25, 2018 If you could give a description to be certain.I'd say yes. Does it have what appears to be little slits in the tops? If so that would be the side that faces outwards. They are ideed slit and squeezed a bit to aid in retention. Much like a nylock nut only no nylon. Link to comment Share on other sites More sharing options...
enginerd Posted February 26, 2018 Report Share Posted February 26, 2018 Can you provide a picture? Pinch nut is not something I’ve heard of in relation to fasteners. Link to comment Share on other sites More sharing options...
Eman911 Posted February 26, 2018 Report Share Posted February 26, 2018 Probably refering to a distorted thread lock nut. If not the only other possibility is that he is refering to doing squats with his driver's suit too tight. Link to comment Share on other sites More sharing options...
turbogrill Posted February 26, 2018 Author Report Share Posted February 26, 2018 1 hour ago, Eman911 said: Probably refering to a distorted thread lock nut. If not the only other possibility is that he is refering to doing squats with his driver's suit too tight. Yes, exactly that is what I meant. Deep squats that is. The seller calls them "flanged pinch nuts". They are the nuts that are used with exhaust studs, there are no washers. I think its this, https://apexfasteners.com/fasteners/nuts/locking-nuts/metal-locking-nuts?zenid=65d957c116bae42a2a504d0120a3a0b4 I wasn't aware that such thing existed, initially I thought I got the wrong thread. Link to comment Share on other sites More sharing options...
enginerd Posted February 26, 2018 Report Share Posted February 26, 2018 Yea, those nuts are referred to in the ASME specification as "prevailing torque lock nuts". There are all metal types as well as nylon insert types... they all do the same thing and are there for the same reason, the idea is that even if the nut is a bit loose, it won't rattle off. Obviously you can't use the nylon style in a high temperature application!! Link to comment Share on other sites More sharing options...
Jer Posted February 26, 2018 Report Share Posted February 26, 2018 This is exactly what I needful my exhaust flange, the nuts keep coming loose and disappearing. Thanks for posting. Link to comment Share on other sites More sharing options...
enginerd Posted February 26, 2018 Report Share Posted February 26, 2018 25 minutes ago, Jer said: This is exactly what I needful my exhaust flange, the nuts keep coming loose and disappearing. Thanks for posting. Look for ones which are specific to exhaust applications. Exhaust hardware can get hot enough to exceed the service temp of zinc plating (which is an extremely common fastener finish). Also, nuts coming loose may be a symptom of some issue other than incorrect hardware. Shifting exhaust.. isolate vibrations with flexi sections.. Link to comment Share on other sites More sharing options...
pintodave Posted February 26, 2018 Report Share Posted February 26, 2018 6 minutes ago, enginerd said: Also, nuts coming loose may be a symptom of some issue other than incorrect hardware. This is known as running 14 hours at Sebring. Link to comment Share on other sites More sharing options...
turbogrill Posted February 26, 2018 Author Report Share Posted February 26, 2018 Why not use a lock washer/split washer on the exhaust? According to wikipedia and NASA they might neccesarily not provide more friction or rotation resistance but might help when slightly loosen. While a normal washer will just fall of once the torque is lost a split washer will still hold a little. Maybe this is why our calipers are using these washers, however they have fallen of in the past.... Link to comment Share on other sites More sharing options...
Technical Advisory Committee Chris Huggins Posted February 26, 2018 Technical Advisory Committee Report Share Posted February 26, 2018 9 minutes ago, turbogrill said: Why not use a lock washer/split washer on the exhaust? According to wikipedia and NASA they might neccesarily not provide more friction or rotation resistance but might help when slightly loosen. While a normal washer will just fall of once the torque is lost a split washer will still hold a little. Maybe this is why our calipers are using these washers, however they have fallen of in the past.... Those lock washers really do not provide much additional friction to prevent the loosening of the fastener. What you really need when you want that to NEVER come off without you doing it is NordLock http://www.nord-lock.com/nord-lock/wedge-locking/washers/introduction/ Also, Locktite is your friend. @Jer If you are having turbo manifold issues, - NORDLOCK is the only way to go, and well worth the frustration to stop having such issues. Be slow and gentle installing the deformed thread nuts. You can fairly easily gall them since they will go on tight the whole way. I usually avoid the ugga-dugga gun when doing this... Tech Article: https://engineerdog.com/2015/01/11/10-tricks-engineers-need-to-know-about-fasteners/ Link to comment Share on other sites More sharing options...
Team Infiniti Posted February 26, 2018 Report Share Posted February 26, 2018 6 minutes ago, turbogrill said: Why not use a lock washer/split washer on the exhaust? Could work but depending on a bunch of factors: FWD/RWD if FWD, flex coupler? driveline "squirm" Rigidity of rest of exhaust system Turbo/NA Why fight using the friction lock unit? Put some high temp anti gall never-seize type of stuff and crank that thing down Link to comment Share on other sites More sharing options...
enginerd Posted February 26, 2018 Report Share Posted February 26, 2018 10 minutes ago, turbogrill said: Why not use a lock washer/split washer on the exhaust? According to wikipedia and NASA they might neccesarily not provide more friction or rotation resistance but might help when slightly loosen. While a normal washer will just fall of once the torque is lost a split washer will still hold a little. Maybe this is why our calipers are using these washers, however they have fallen of in the past.... Whatever thing/event/circumstance caused the nut to rotate a little bit will probably happen a couple more times before the end of the race. The split lock washer is going to be very ineffective at preventing nut rotation on the second, third, etc. instances. The lock nut will keep grabbing the thread the whole way off, so perhaps you now have a tiny exhaust leak, but the nut doesn’t loosen as much as others would. The nordlock washers actually tighten the joint as the nut is initially turned to loosen Link to comment Share on other sites More sharing options...
JDChristianson Posted February 26, 2018 Report Share Posted February 26, 2018 Longer bolt an double nut?? Link to comment Share on other sites More sharing options...
Originalsterm Posted February 26, 2018 Report Share Posted February 26, 2018 19 minutes ago, Huggy said: Those lock washers really do not provide much additional friction to prevent the loosening of the fastener. What you really need when you want that to NEVER come off without you doing it is NordLock http://www.nord-lock.com/nord-lock/wedge-locking/washers/introduction/ Also, Locktite is your friend. @Jer If you are having turbo manifold issues, - NORDLOCK is the only way to go, and well worth the frustration to stop having such issues. Be slow and gentle installing the deformed thread nuts. You can fairly easily gall them since they will go on tight the whole way. I usually avoid the ugga-dugga gun when doing this... Tech Article: https://engineerdog.com/2015/01/11/10-tricks-engineers-need-to-know-about-fasteners/ Heico-Lock and Disc-Lock in addition to Nordlock if you are looking for other options with the same design/premise. Dual slotted, all metal, self-locking hex nuts are great when the nylon lock nuts most people are use to can't stand up to the heat of exhaust and you get get one of the above mentioned washers in there. Link to comment Share on other sites More sharing options...
Ogren-Engineering Posted February 26, 2018 Report Share Posted February 26, 2018 No washer at all works verywell. Link to comment Share on other sites More sharing options...
Jer Posted February 26, 2018 Report Share Posted February 26, 2018 8 minutes ago, Ogren-Engineering said: No washer at all works verywell. Learned this from experience. The Nordlock looks like the best idea. We have a flex pipe already. Link to comment Share on other sites More sharing options...
Slugworks Paul Posted February 26, 2018 Report Share Posted February 26, 2018 Nate wins the thread! Perhaps because he used to be a hardware applications engineer Link to comment Share on other sites More sharing options...
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