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Torquing Nylon Nuts? Oops.
- Thread starter cactusman
- Start date
Clamp the broken bolt in a vise and use it to practice using the torque wrench.
The snap type torque wrenches are very difficult to feel the torque break at that low of a setting, especially for someone not familiar with them.
BTW, the yield point on an AN3 bolt begins at about 65 inch pounds, so to twist it off you had to go beyond that.
The snap type torque wrenches are very difficult to feel the torque break at that low of a setting, especially for someone not familiar with them.
BTW, the yield point on an AN3 bolt begins at about 65 inch pounds, so to twist it off you had to go beyond that.
You torque nuts to bring the bolt to a pre-load, to maximize ultimate strength. Strictly speaking there are different ideal preloads for shear vs tension loads, but most just use one setting.
Short answer: yes, torque nylon lock nuts. Add the drag of the nylon to 25 in lbs for AN3.
You may have had a defective bolt, but I would have your torque wrench checked. 25 in lbs is easy to surpass with little effort.
Short answer: yes, torque nylon lock nuts. Add the drag of the nylon to 25 in lbs for AN3.
You may have had a defective bolt, but I would have your torque wrench checked. 25 in lbs is easy to surpass with little effort.
cactusman
Well Known Member
Wow that was fast....!
Thx all. I think it was a new (used) wrench I picked up for the inch lbs and the smaller bolts. It is hard to feel the bump (click) that got me to the point of 25 lbs - it is really not much force at all. I tried the second one much more delicately and it "clicked" fine. Not sure what happened the first time.
It sure didn't feel like a lot of force to twist it either and it kind of freaked me out because this is a pretty important bolt to say the least. Just got carried away I guess.
flion
Well Known Member
It's funny but 25 in/lbs doesn't feel like much; most of the time you'd breeze right past it without a torque wrench. My first time, I somehow had the impression that the wrench would stop wrenching at the set torque so I way overdid it. Then someone showed me how a click-style torque wrench worked. 
What can I say? Previously I had only used a beam wrench on my motorcycles and cars.
What can I say? Previously I had only used a beam wrench on my motorcycles and cars.David Paule
Well Known Member
Measuring Running Torque
I bought one of these to measure the running torque on nuts. As Bob said in post #4, you add that torque to the specified torque. Example, you start to thread the nut on and when the bolt is more than a full thread through the locking region of the nut, but still not bottomed out, switch to this tool and measure what the torque is from just the locking element. Then add that to whatever is specified in the plans. Set your clicker to this sum or alternatively, simply continue to use this.
http://www.amazon.com/2955-Torque-Wrench-0-60-Inch-Pounds/dp/B00004SQ3B
Dave
I bought one of these to measure the running torque on nuts. As Bob said in post #4, you add that torque to the specified torque. Example, you start to thread the nut on and when the bolt is more than a full thread through the locking region of the nut, but still not bottomed out, switch to this tool and measure what the torque is from just the locking element. Then add that to whatever is specified in the plans. Set your clicker to this sum or alternatively, simply continue to use this.
http://www.amazon.com/2955-Torque-Wrench-0-60-Inch-Pounds/dp/B00004SQ3B
Dave
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