15 pack of clone bolts are
here
Quote:
The first few threads of the nut will support the majority of the load. Research has shown in some cases involving UNC threaded nuts that the first thread will have to support nearly 35% of the load. The second thread will support about 25% of the load, and the third thread about 18%. In this case the first three threads support 78% of the load.
To allow this distribution, nut threads are designed to be softer than bolt thread and will conform to the contour of the bolt threads when tensioned. If a nut were reused, there would no longer be a "ideal" thread match. This will create more friction between the threads during installation, which will significantly alter the installation torque.
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So, probably should replace the nut even if you keep the bolt or it throws off the torque to tension ratio dramatically.
Quote:
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n a demonstration with a 1/2-13 zinc plated SAE J429 Grade 5 hex cap screw and zinc plated SAE J995 Grade 5 hex nut with an installation torque of 70 ft-lbs to obtain a clamp load of 9000 lbs (without any added lubrication). On the second installation, this torque had increased to 95 ft-lbs to obtain 9000 lbs. By the fourth installation, we required 145 ft-lbs to reach a clamp load of 9000 lbs.
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So it would seem the factor that changes the torque required the most is the nut. Learning new things every day. So, i'm thinking i'll be using NORMAL nuts and locktite and i'll replace the nuts rather than lubricate them, but the final solution will depend on the with or without lubrication and using new nuts.
On the other hand, i just found the T-slot nuts that are 12.9 to match my upcoming 12.9 bolts, i'm hoping i can get them to fit up top without room to turn so they are self-stopping no need to reach up to hold the nut.