It's easy enough. you can make yourself a small device to put letters into it to form whole words, then stamp those onto the metal cards or do it letter by letter. Just make sure those stencils are of solid metal and not some cheap aluminium stuff.

Alternative you can get metal 12-24 metal washers and stamp a word on each one of those. Put them onto a screw and secure those with a nut.

nostr:npub1lrjgpa9m2dl6esdah5pq7m005ymwh4glq4aet76q2zlz2f83esfsa2zvrj has a cool gadget to help you with those.

https://www.cryptocloaks.com/product/blockmitjig/aff/thegrinder/