we are trying to do a small test study on one of the crank shafts bolts. we know that the operating condistions of the shaft produces a clyclic load of 5000 lbs on the joint.
how much (any rule of thumb?) preload should I use inorder the joint dosent come loose after a test.
anything over 5000...
I would agree with Desertfox and Cory.
Generally the material specs would be "min" specs.If you are right exactly at the min spec then u "might" not see any joint failure.Based on the accuracy of the tool, if you over torque, then there might be possible damage to the bracket and eventually...
Cory and Minjulep,
Yes the audit purpose is to check if our operators are doing thier job. we just wanna check the retaining torque.
we got some datamytes which when rotate the fastener less than 5 degrees give you the torque and gives a sound and light signal.
red - out of spec (high)
green -...
What is the best audit procedure for the bolted joints?
For example If Assembly torque – 20-30 Nm
Audit with in 15 min – 17-33 Nm (+/- 15%) for hard joints
And 14-36 Nm (+/-30%) for gasketed/soft joints
Is this a good assumption to start with? Valuable suggestions needed.
Nicke,
Instead of doing multiple pass tightening, why cant we have a clicker wrench set at target torque and make sure all of them reached the torque. This would save more time than doing multiple pass right?
correct me if I am wrong
Nicke,
Thanks for the explanation.Sounds good to me.But is this process feasible on production line?????? dosent this kill extra time,labor charges and more cost???
Cory,
Thanks for the refrences. Will do that
simultanoeous is not possible. we are using single spindle dc tool. yes we are doing cross pattern to minimise the effect of cross talk.
clamp load is good. we dont have any failures in that aspect. the only problem is for some of the assembly rundowns we are hitting our max angle of 750 deg...
Joint is a 6 bolt joint and soft one with a gasket in between. We are using torque control angle monitor shut off strategy.
Torque – 240-260 in-lbs
Angle shut off monitor limit – 750 deg
Snug – 25 in-lbs (random guess)
We are using 750 deg monitor because the very first bolt in that soft joint...
Desertfox,
For some reason my handle "preload" is not working. It says some registrations problems. So I created a new handle.
Anyway, the witness ring you are seeing is just the washer taking the paint away on the surface. I dint feel or see and step under the washer.
But yes It would be a...