07-01-2018, 07:30 PM
Thank you for all your responses,
The 3 set screws which failed are zinc plated 1/4” and are 3/4” long grade R, one was dry assembled, because I planed to remove it again, the other two I was fitting to stay and had lightly oiled.
All of these fasteners are going into my chassis to replace the unplanted R grade ones used during the build. At the time I assembled the chassis using liberal applications of Wax Oil, indeed all of these original fasteners threads are thick with it, but they took the appropriate ft. lbs. torque without a problem.
You may be wondering why I felt compelled to change them;
Firstly, they have had repeated use during the build, so some stretch and thread wear was inevitable, secondly, I am expecting that as I shake down the car, that either due to vibration or unexpected stresses, some of these fasteners will need tightening, some of them repeatedly, it is amazing how vibration affects track cars, as such I did not want them covered in paint or difficult to inspect. I also did not want any crossion issues with them.
Clive, if you have the facility do a destructive test, that would be very interesting. My concern here is that the fault lies with me, so clarity on the viability of the fasteners would be most enlightening.
Regards, Mark
The 3 set screws which failed are zinc plated 1/4” and are 3/4” long grade R, one was dry assembled, because I planed to remove it again, the other two I was fitting to stay and had lightly oiled.
All of these fasteners are going into my chassis to replace the unplanted R grade ones used during the build. At the time I assembled the chassis using liberal applications of Wax Oil, indeed all of these original fasteners threads are thick with it, but they took the appropriate ft. lbs. torque without a problem.
You may be wondering why I felt compelled to change them;
Firstly, they have had repeated use during the build, so some stretch and thread wear was inevitable, secondly, I am expecting that as I shake down the car, that either due to vibration or unexpected stresses, some of these fasteners will need tightening, some of them repeatedly, it is amazing how vibration affects track cars, as such I did not want them covered in paint or difficult to inspect. I also did not want any crossion issues with them.
Clive, if you have the facility do a destructive test, that would be very interesting. My concern here is that the fault lies with me, so clarity on the viability of the fasteners would be most enlightening.
Regards, Mark