One of Mary’s quilting group arrived with a machine in dire need of cleaning and oiling. These screws hold the throat plate in place:
They’re standing in a pair of threaded brass inserts (found in the benchtop litter) to show off their tops.
The left screw came out easily, although a few licks with a fine file eased the slot corners.
The one on the right, however, was firmly jammed in place, with the crappy little Kenmore sewing machine screwdriver causing the goobering. I deployed my Brownell’s Gunsmith Screwdriver Bits, applied slightly less force than would ordinarily call for an overnight penetrating oil session, got the screw out, and cleaned it up:
A dot of oil on the threads should keep it happy for the foreseeable future.