East German Side Folder Screw

I was surprised at the setup of using a thick-head 5mm metric screw and a matching countersink washer. Is this a normal E Germany side-folding stock setup? Not sure! I'm goin to put this screw/washer combination to the test! I'm going to remount my factory Polish Tantal Wz88 wire side-folding stock using these screws with a lil' threadlocker to boot. They should work fine for anchoring the stock w