onowino said:IslandTractor, I don't see any way to use a castle nut.
A 5/8" bolt passes through the blade and screws into the spindle. The spindle has no threaded shaft arbor, or a castle nut would be the answer.
I guess this thread has run its course.
Thanks to everybody who contributed their thoughts.
The problem still remains, but I guess it's mine.
Fred
----------------------------------------------------------------------------------------How are you tightening the bolts. If they are grade 5 they should be torqued to 150lbs if grade 8 230lbs. With locktight and proper torque I would think it would hold mowing grass.
Bill
-----------------------------------------------------------------------------------------interesting problem ...if you are willing to work really hard when you next need to take the blades off, consider some variant (along with loctite) of the following woodworkers trick:
slit the bolt lengthwise some distance with, say, a dremel cutting wheel ...gently insert a slim taper wedge sized so it will bottom out and drive itself into the bolt and expand the threads.
If you decide to consider some variant of this, let me know how/if it works to your satisfaction.
I also thought that the idea of distorting some of the latter threads might work; did you try that?