Originally Posted by
merziac
I would go to the hardware store and get some high quality screws/bolts and either/and/or grind a taper on the starting end and carefully file or cut some slots along at least two sides to make a chaser to clear out the paint.
I'd just do it right and buy the tap. I can't believe a metric tap wouldn't be on the shelf in a German HW store and not that expensive.
I'd also get a M10x1.0 tap for RD hanger threads as long as I was buying. .