Left hand threads

Just built a 12 station cabbing machine for the missus for grinding her gems (10 wheels and 2 flat plates, one either end)
Left one has LH thread, right one has RH thread, come undone otherwise, all the grinding wheels are tightened onto spare collars by the 2 outer wheels.

"Automobiles have also used left-threaded lug nuts on left-side wheels, but now commonly use tapered lug nuts, which do not precess."
Holy Snapping Duck ---t ! I had to look up Wikipedia to even find out what that meant!
Back to the books!
Now, I guess the next dumb question is, the nuts have to be specially formed to suit the countersink in the rim mounting holes?? What if there is no taper, or bevel on the rim holes?
Pointless putting a flat washer on, probably even more so using a spring washer, you would have to replace them everytime you removed a wheel for any reason, from the L/H side of the vehicle?
Wished I'd never started this, better off trying to locate some spare L/H wheel mounting studs/bolts/nuts.
Dave

Here is one answer for every type of nut.

www.hobson.com.au/files/other/nord-lock-...product-brochure.pdf