Last night there was a post about the use of never seize on driveshaft bolts. I admit that I use the stuff on just about everything and assumed that I need to back off the torque values by 10% to compensate for the reduced friction never seize provides.
Having never seen any data on how never seize impacts bolt torque values, and being an engineer, I decided to do a little test tonight.
Now first off, there are a number of ways this test can be criticized, but due to the limitations of materials and time, I think the method I used was fairly credible and semi-repeatable for a lug nut scenario.
Here is what I did.
I first rounded up some new jeep lug nuts and a ½ inch mighty fine bolt to simulate my wheel lug. I then drilled out a piece of steel and created a tapered interface for the lug to sit in using some larger drill bits and a die grinder.
I then sandwiched two pieces of rubber mud flap between the tapered interface and some high strength washers to created a squishable doughnut that I could take compressed measurements off of.
I took compressed measurements between 20 ft*lbs and 110 ft*lbs. For sequences 1-3, I used the same lug and nut with no never seize.
For Sequences 4 and 5, I used the same lug and nut, but with ample amounts of never seize on the threads and where the nut would sit in the tapered interface. Since never seize seems to get just about everywhere, I figured some would eventually end up on the mating surface of the lug nut.
For sequence 6, I used brake cleaner to remove the never seize and mimicked the 1-3 sequence. The values for this sequence was off a little, but my tapered interface was getting smoother with each sequence.
The results where so startling, that I re-ran the test with a new lug nut. Sequence 7 was new lug and dry, Sequence 8 was same lug but never seized.
Sequence 9 had never seize on the threads, but nothing on the tapered interface.
You can see the graphs for yourselves, but basically if you get never seize on the tapered interface, a 30-40 ft*lb torque using never seize is equivalent to 100 ft*lb torque without never seize.
With sequence 9, the values were very close to the dry bolt so moral of the story appears to be “don’t put never seize on the mating surface of lug nuts”.
Although more testing is required, it appears putting never seize on just the threads of a bolt may have very little impact on torque values. If I get around to it tomorrow, I’ll run some tests on a simple bolt.
Any thoughts/conclusions from the data I collected?
Adam
Having never seen any data on how never seize impacts bolt torque values, and being an engineer, I decided to do a little test tonight.
Now first off, there are a number of ways this test can be criticized, but due to the limitations of materials and time, I think the method I used was fairly credible and semi-repeatable for a lug nut scenario.
Here is what I did.
I first rounded up some new jeep lug nuts and a ½ inch mighty fine bolt to simulate my wheel lug. I then drilled out a piece of steel and created a tapered interface for the lug to sit in using some larger drill bits and a die grinder.
I then sandwiched two pieces of rubber mud flap between the tapered interface and some high strength washers to created a squishable doughnut that I could take compressed measurements off of.
I took compressed measurements between 20 ft*lbs and 110 ft*lbs. For sequences 1-3, I used the same lug and nut with no never seize.
For Sequences 4 and 5, I used the same lug and nut, but with ample amounts of never seize on the threads and where the nut would sit in the tapered interface. Since never seize seems to get just about everywhere, I figured some would eventually end up on the mating surface of the lug nut.
For sequence 6, I used brake cleaner to remove the never seize and mimicked the 1-3 sequence. The values for this sequence was off a little, but my tapered interface was getting smoother with each sequence.
The results where so startling, that I re-ran the test with a new lug nut. Sequence 7 was new lug and dry, Sequence 8 was same lug but never seized.
Sequence 9 had never seize on the threads, but nothing on the tapered interface.
You can see the graphs for yourselves, but basically if you get never seize on the tapered interface, a 30-40 ft*lb torque using never seize is equivalent to 100 ft*lb torque without never seize.
With sequence 9, the values were very close to the dry bolt so moral of the story appears to be “don’t put never seize on the mating surface of lug nuts”.
Although more testing is required, it appears putting never seize on just the threads of a bolt may have very little impact on torque values. If I get around to it tomorrow, I’ll run some tests on a simple bolt.
Any thoughts/conclusions from the data I collected?
Adam
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