Washer Between Jam Nuts Prevent Wrench Slippage
I found that the best way to install threaded inserts is to use my drill press (unplugged, of course) as a heavy-duty manual press. The press gives the insert a straight start and supplies enough pressure to drive it into harder woods.
If you have done this before, you know that the wrench slips off the top jam nut pretty easily, so I placed a flat washer between the first and second jam nuts. The wrench can't slip off the nut because the washer blocks it.
—Perry Johnson, Golden Valley, Minn.