Round corner punch.
https://diqn32j8nouaz.cloudfront.net...e_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...234#post165540
https://www.homemadetools.net/forum/...618#post139635
https://www.homemadetools.net/forum/...010#post176061
https://www.homemadetools.net/forum/...833#post152447
https://www.homemadetools.net/forum/...520#post201011
