Hook socket for wooden rod

Fix it with a 4mm screw to something. Push something round into it and use it as a hook or what ever floats your boat. The hole is tolerated with +0.2 mm in diameter. My 21.7 mm thick and about 70 mm long pole fit in very snugly and won't come out by accident. It has a slight unknown angle. Like a proper hook thing.

21.7 mm

20 mm

1 inch or 25.4 mm

¾ inch or 19 mm

P.S.: Only after installation I noticed an unfortunate resemblance…