I thought about this method. It costs around $3 in my country if you already have hammer and stapms

030e0dca83

Just milled metal. Lots of less fancy ways.  My personal punk rock version is just hammered washers.  You can 3d print a jig to keep it clean too. 
https://blockmit.com/english/guides/diy/make-cold-wallet-washers/


RDClark

bitcoin

Happy recovery day

I totally support you. It's great we study Bitcoin. But I don't have a plan to take Bitcoin to the grave that's why I should teach people around me

btw, checked your storage device. It looks fancy. I'm curious, is it possible to make it myself...