Original Posted By: John McNarry
Yes a bolt in tension should be tightened enoughto exceed load placed on the bolt that way it does'ntcycle thousands of times fatigueing then breaking.one time a couple of good old boys and me boughta tx-1000 utltralight, there was a bolt passing throughthe root tube holding a spar bracket on. It broke with myfriend in flight. I picked up my helmet and was walking outto meet him as he landed. As his taxi slowed the wingliterally fell off, seems there were a couple of threadsleft on the bolt and as long as the bracket lifted upit was caught on the broken bolt however when the liftended the wing fell off. My friend says he heard thebolt break!-----Original Message-----
Pietenpol-List: torque specs
Pietenpol-List: Re: torque specs
Original Posted By:>>> Dean Dayton
Subject: Pietenpol-List: Re: torque specs>Are you saying that a 3/8 bolt should be torqued to less than 16 ft->lb? Doesn't this seem low?>>>>.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft.>190 lbs>>-in.is only 16 lbs ft.>> Doug>>>>----------
Subject: Pietenpol-List: Re: torque specs>Are you saying that a 3/8 bolt should be torqued to less than 16 ft->lb? Doesn't this seem low?>>>>.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft.>190 lbs>>-in.is only 16 lbs ft.>> Doug>>>>----------
> Re: torque specs
Original Posted By:>>>> Dean Dayton
Subject: Pietenpol-List: Re: torque specs>Is the bolt in shear or tension?> In tension the torque is more critical as it should be enought to>establish a preload on the bolt. (The bolt should have more internaltension>on it than the loads imposed by its application.) In shear the torque needs>to be only enough to eliminate end play and provide enough resistance to>rotation. ( the reason most bolts are safetied.)>>John Mc>-----Original Message----->From: Dean Dayton >To: Pietenpol Discussion >Date: Thursday, April 22, 1999 7:01 PM>Subject: Re: torque specs>>>>Are you saying that a 3/8 bolt should be torqued to less than 16 ft->>lb? Doesn't this seem low?>>>>>>>.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft.>>190 lbs>>>-in.is only 16 lbs ft.>>> Doug>>>>>>----------
Subject: Pietenpol-List: Re: torque specs>Is the bolt in shear or tension?> In tension the torque is more critical as it should be enought to>establish a preload on the bolt. (The bolt should have more internaltension>on it than the loads imposed by its application.) In shear the torque needs>to be only enough to eliminate end play and provide enough resistance to>rotation. ( the reason most bolts are safetied.)>>John Mc>-----Original Message----->From: Dean Dayton >To: Pietenpol Discussion >Date: Thursday, April 22, 1999 7:01 PM>Subject: Re: torque specs>>>>Are you saying that a 3/8 bolt should be torqued to less than 16 ft->>lb? Doesn't this seem low?>>>>>>>.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft.>>190 lbs>>>-in.is only 16 lbs ft.>>> Doug>>>>>>----------
Pietenpol-List: torque specs
Original Posted By: Doug
I just looked in the "Standard Aircraft Handbook" for the torque spces on a 3/8 inch bolt (fine thread, standard nut). It said "160-190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-lightyear, or what?Dean Dayton - deandayton(at)hotmail.com ________________________________________________________________________________
I just looked in the "Standard Aircraft Handbook" for the torque spces on a 3/8 inch bolt (fine thread, standard nut). It said "160-190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-lightyear, or what?Dean Dayton - deandayton(at)hotmail.com ________________________________________________________________________________
Pietenpol-List: Re: torque specs
Original Posted By:> Dean Dayton
.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. 190 lbs-in.is only 16 lbs ft. Doug
.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. 190 lbs-in.is only 16 lbs ft. Doug
Pietenpol-List: Re: torque specs
Original Posted By:>> Dean Dayton
Are you saying that a 3/8 bolt should be torqued to less than 16 ft-lb? Doesn't this seem low?>.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. 190 lbs>-in.is only 16 lbs ft.> Doug>>----------
Are you saying that a 3/8 bolt should be torqued to less than 16 ft-lb? Doesn't this seem low?>.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. 190 lbs>-in.is only 16 lbs ft.> Doug>>----------
Pietenpol-List: Re: torque specs
Original Posted By:> Dean Dayton
NO,I'AM saying that 16lbs-ft,is = to 190 lbs-inches.And that the unitsimplied by your book are in lbs-inches and not lbs-ft,thats all. It would depend on what you are bolting together,ie;wood or metal,are theyin shear or tension etc,etc. Just for a non aircraft example,a con.rod nut on a 350 Chevy which is3/8nf thread,is torqued to 45 lbs-ft,this stretches the bolt and keeps thenon locking nut from departing.Most new engine specs are given in a lowbase torque,then X number of degrees added rotation,ie 20 lbs-ft plus 90degrees,this is torque to yield,stetching the bolt for maxclamping(tension).These bolts are used ONCE then tosed. Doug..
NO,I'AM saying that 16lbs-ft,is = to 190 lbs-inches.And that the unitsimplied by your book are in lbs-inches and not lbs-ft,thats all. It would depend on what you are bolting together,ie;wood or metal,are theyin shear or tension etc,etc. Just for a non aircraft example,a con.rod nut on a 350 Chevy which is3/8nf thread,is torqued to 45 lbs-ft,this stretches the bolt and keeps thenon locking nut from departing.Most new engine specs are given in a lowbase torque,then X number of degrees added rotation,ie 20 lbs-ft plus 90degrees,this is torque to yield,stetching the bolt for maxclamping(tension).These bolts are used ONCE then tosed. Doug..
Pietenpol-List: Re: torque specs
Original Posted By: Dean Dayton
Is the bolt in shear or tension? In tension the torque is more critical as it should be enought toestablish a preload on the bolt. (The bolt should have more internal tensionon it than the loads imposed by its application.) In shear the torque needsto be only enough to eliminate end play and provide enough resistance torotation. ( the reason most bolts are safetied.)John Mc-----Original Message-----
Is the bolt in shear or tension? In tension the torque is more critical as it should be enought toestablish a preload on the bolt. (The bolt should have more internal tensionon it than the loads imposed by its application.) In shear the torque needsto be only enough to eliminate end play and provide enough resistance torotation. ( the reason most bolts are safetied.)John Mc-----Original Message-----
Pietenpol-List: Re: torque specs
Original Posted By:>> Dean Dayton
Sorry, didn't mean to sound critical. I was just trying to figure out why my auto mechanic friends were giving me much higher torque values than the aircraft manuals.Let me restate what you said (so you can tell me if I've go it right;-). The higher torque values are based on the assumption that the bolt will be permanently deformed (and less strength?) and should not be reused (but it saves a few cents by using a non-locking nut).Thanks for your help>NO,I'AM saying that 16lbs-ft,is = to 190 lbs-inches.And that the units>implied by your book are in lbs-inches and not lbs-ft,thats all.> It would depend on what you are bolting together,ie;wood or metal,are they>in shear or tension etc,etc.> Just for a non aircraft example,a con.rod nut on a 350 Chevy which is>3/8nf thread,is torqued to 45 lbs-ft,this stretches the bolt and keeps the>non locking nut from departing.Most new engine specs are given in a low>base torque,then X number of degrees added rotation,ie 20 lbs-ft plus 90>degrees,this is torque to yield,stetching the bolt for max>clamping(tension).These bolts are used ONCE then tosed.> Doug..>----------
Sorry, didn't mean to sound critical. I was just trying to figure out why my auto mechanic friends were giving me much higher torque values than the aircraft manuals.Let me restate what you said (so you can tell me if I've go it right;-). The higher torque values are based on the assumption that the bolt will be permanently deformed (and less strength?) and should not be reused (but it saves a few cents by using a non-locking nut).Thanks for your help>NO,I'AM saying that 16lbs-ft,is = to 190 lbs-inches.And that the units>implied by your book are in lbs-inches and not lbs-ft,thats all.> It would depend on what you are bolting together,ie;wood or metal,are they>in shear or tension etc,etc.> Just for a non aircraft example,a con.rod nut on a 350 Chevy which is>3/8nf thread,is torqued to 45 lbs-ft,this stretches the bolt and keeps the>non locking nut from departing.Most new engine specs are given in a low>base torque,then X number of degrees added rotation,ie 20 lbs-ft plus 90>degrees,this is torque to yield,stetching the bolt for max>clamping(tension).These bolts are used ONCE then tosed.> Doug..>----------
Pietenpol-List: Re: torque specs
Original Posted By: Doug Sheets
The first book I came to in my library was a Cessna 172 Maintenance Manual. On page 1-3 of this publication is a chart that describes "Recommended Nut Torques". For tension, a 3/8-24 bolt using AN310, AN345, AN362, AN363, AN366, MS20365, "1452", "EB", "UWN", "Z1200" and other self locking nuts is torqued to 160-190 pound-inches on oil-free cadmium plated threads. A 3/8-24 bolt in shear using AN316, AN320, AN7502 or MS20364 is torqued to 95-110 pound inches, again on oil-free cadmium plated threads. I'll check my AC43-13, but I'm sure itr will say the same.Ed________________________________________________________________________________
The first book I came to in my library was a Cessna 172 Maintenance Manual. On page 1-3 of this publication is a chart that describes "Recommended Nut Torques". For tension, a 3/8-24 bolt using AN310, AN345, AN362, AN363, AN366, MS20365, "1452", "EB", "UWN", "Z1200" and other self locking nuts is torqued to 160-190 pound-inches on oil-free cadmium plated threads. A 3/8-24 bolt in shear using AN316, AN320, AN7502 or MS20364 is torqued to 95-110 pound inches, again on oil-free cadmium plated threads. I'll check my AC43-13, but I'm sure itr will say the same.Ed________________________________________________________________________________
Pietenpol-List: Re: torque specs
Original Posted By:> Dean Dayton
Don't be sorry,the reasons for torque to yeild are not cost related,butfor max clamping etc.Maybe too much info? Regards Doug
Don't be sorry,the reasons for torque to yeild are not cost related,butfor max clamping etc.Maybe too much info? Regards Doug
> torque specs
Original Posted By: Dean Dayton
> > I just looked in the "Standard Aircraft Handbook" for the torque > spces on a 3/8 inch bolt (fine thread, standard nut). It said "160-> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-> lightyear, or what?> > > Dean Dayton - deandayton(at)hotmail.com > > ________________________________________________________________________________
> > I just looked in the "Standard Aircraft Handbook" for the torque > spces on a 3/8 inch bolt (fine thread, standard nut). It said "160-> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-> lightyear, or what?> > > Dean Dayton - deandayton(at)hotmail.com > > ________________________________________________________________________________
>> torque specs
Original Posted By: John Fay
>> >> I just looked in the "Standard Aircraft Handbook" for the torque >> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->> lightyear, or what?>> >> >> Dean Dayton - deandayton(at)hotmail.com >> >> ________________________________________________________________________________
>> >> I just looked in the "Standard Aircraft Handbook" for the torque >> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->> lightyear, or what?>> >> >> Dean Dayton - deandayton(at)hotmail.com >> >> ________________________________________________________________________________
>>> torque specs
Original Posted By: Doug
>>>>>> I just looked in the "Standard Aircraft Handbook" for the torque>>> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->>> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->>> lightyear, or what?>>>>>>>>> Dean Dayton - deandayton(at)hotmail.com>>>>>>>>________________________________________________________________________________
>>>>>> I just looked in the "Standard Aircraft Handbook" for the torque>>> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->>> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->>> lightyear, or what?>>>>>>>>> Dean Dayton - deandayton(at)hotmail.com>>>>>>>>________________________________________________________________________________
> Re: torque specs
Original Posted By:> >> Dean Dayton
> > Are you saying that a 3/8 bolt should be torqued to less than 16 ft-> lb? Doesn't this seem low?> > > >.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. > 190 lbs> >-in.is only 16 lbs ft.> > Doug> >> >----------
> > Are you saying that a 3/8 bolt should be torqued to less than 16 ft-> lb? Doesn't this seem low?> > > >.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. > 190 lbs> >-in.is only 16 lbs ft.> > Doug> >> >----------
> >> torque specs
Original Posted By: kyle ray
> >> > >> I just looked in the "Standard Aircraft Handbook" for the torque > >> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160-> >> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-> >> lightyear, or what?> >> > >> > >> Dean Dayton - deandayton(at)hotmail.com > >> > >> > > ________________________________________________________________________________
> >> > >> I just looked in the "Standard Aircraft Handbook" for the torque > >> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160-> >> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-> >> lightyear, or what?> >> > >> > >> Dean Dayton - deandayton(at)hotmail.com > >> > >> > > ________________________________________________________________________________
>>>> torque specs
Original Posted By: oil can
>>>>>>>> I just looked in the "Standard Aircraft Handbook" for the torque>>>> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->>>> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->>>> lightyear, or what?>>>>>>>>>>>> Dean Dayton - deandayton(at)hotmail.com>>>>>>>>>>>>>________________________________________________________________________________
>>>>>>>> I just looked in the "Standard Aircraft Handbook" for the torque>>>> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->>>> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->>>> lightyear, or what?>>>>>>>>>>>> Dean Dayton - deandayton(at)hotmail.com>>>>>>>>>>>>>________________________________________________________________________________
>> Re: torque specs
Original Posted By:>> >> Dean Dayton
>> >> Are you saying that a 3/8 bolt should be torqued to less than 16 ft->> lb? Doesn't this seem low?>> >> >> >.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. >> 190 lbs>> >-in.is only 16 lbs ft.>> > Doug>> >>> >----------
>> >> Are you saying that a 3/8 bolt should be torqued to less than 16 ft->> lb? Doesn't this seem low?>> >> >> >.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. >> 190 lbs>> >-in.is only 16 lbs ft.>> > Doug>> >>> >----------
>> >> torque specs
Original Posted By: Brian Ippolito
>> >> >> >> I just looked in the "Standard Aircraft Handbook" for the torque >> >> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->> >> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->> >> lightyear, or what?>> >> >> >> >> >> Dean Dayton - deandayton(at)hotmail.com >> >> >> >> >> >> ________________________________________________________________________________
>> >> >> >> I just looked in the "Standard Aircraft Handbook" for the torque >> >> spces on a 3/8 inch bolt (fine thread, standard nut). It said "160->> >> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton->> >> lightyear, or what?>> >> >> >> >> >> Dean Dayton - deandayton(at)hotmail.com >> >> >> >> >> >> ________________________________________________________________________________
> Re: torque specs
Original Posted By:> >> Dean Dayton
> > Sorry, didn't mean to sound critical. I was just trying to figure out > why my auto mechanic friends were giving me much higher torque values > than the aircraft manuals.> > Let me restate what you said (so you can tell me if I've go it > right;-). The higher torque values are based on the assumption that > the bolt will be permanently deformed (and less strength?) and should > not be reused (but it saves a few cents by using a non-locking nut).> > Thanks for your help> > > > >NO,I'AM saying that 16lbs-ft,is = to 190 lbs-inches.And that the > units> >implied by your book are in lbs-inches and not lbs-ft,thats all.> > It would depend on what you are bolting together,ie;wood or > metal,are they> >in shear or tension etc,etc.> > Just for a non aircraft example,a con.rod nut on a 350 Chevy which > is> >3/8nf thread,is torqued to 45 lbs-ft,this stretches the bolt and > keeps the> >non locking nut from departing.Most new engine specs are given in a > low> >base torque,then X number of degrees added rotation,ie 20 lbs-ft plus > 90> >degrees,this is torque to yield,stetching the bolt for max> >clamping(tension).These bolts are used ONCE then tosed.> > Doug..> >----------
> > Sorry, didn't mean to sound critical. I was just trying to figure out > why my auto mechanic friends were giving me much higher torque values > than the aircraft manuals.> > Let me restate what you said (so you can tell me if I've go it > right;-). The higher torque values are based on the assumption that > the bolt will be permanently deformed (and less strength?) and should > not be reused (but it saves a few cents by using a non-locking nut).> > Thanks for your help> > > > >NO,I'AM saying that 16lbs-ft,is = to 190 lbs-inches.And that the > units> >implied by your book are in lbs-inches and not lbs-ft,thats all.> > It would depend on what you are bolting together,ie;wood or > metal,are they> >in shear or tension etc,etc.> > Just for a non aircraft example,a con.rod nut on a 350 Chevy which > is> >3/8nf thread,is torqued to 45 lbs-ft,this stretches the bolt and > keeps the> >non locking nut from departing.Most new engine specs are given in a > low> >base torque,then X number of degrees added rotation,ie 20 lbs-ft plus > 90> >degrees,this is torque to yield,stetching the bolt for max> >clamping(tension).These bolts are used ONCE then tosed.> > Doug..> >----------
> >> Re: torque specs
Original Posted By:> >> >> Dean Dayton
> >> > >> Are you saying that a 3/8 bolt should be torqued to less than 16 > ft-> >> lb? Doesn't this seem low?> >> > >> > >> >.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. > >> 190 lbs> >> >-in.is only 16 lbs ft.> >> > Doug> >> >> >> >----------
> >> > >> Are you saying that a 3/8 bolt should be torqued to less than 16 > ft-> >> lb? Doesn't this seem low?> >> > >> > >> >.A 3/8 bolt will fail long long before you ever reach 160 lbs- ft. > >> 190 lbs> >> >-in.is only 16 lbs ft.> >> > Doug> >> >> >> >----------
> >> >> torque specs
Original Posted By: Jim
> >> >> > >> >> I just looked in the "Standard Aircraft Handbook" for the torque > >> >> spces on a 3/8 inch bolt (fine thread, standard nut). It said > "160-> >> >> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-> >> >> lightyear, or what?> >> >> > >> >> > >> >> Dean Dayton - deandayton(at)hotmail.com > >> >> > >> >> > >> > >> > > ________________________________________________________________________________
> >> >> > >> >> I just looked in the "Standard Aircraft Handbook" for the torque > >> >> spces on a 3/8 inch bolt (fine thread, standard nut). It said > "160-> >> >> 190". It didn't give any units. Is this inch-lbs, ft-lbs, ton-> >> >> lightyear, or what?> >> >> > >> >> > >> >> Dean Dayton - deandayton(at)hotmail.com > >> >> > >> >> > >> > >> > > ________________________________________________________________________________