Phil that one I linked to goes down to 0.4mm rivit heads, said to be suitable for 00/HO scale which would suggest a shank of 0.2mm dia if they were real rivits which I would class as quite small.
It does say there is an adjustment for spacing so assume you can set that to get regular placement of the dummy rivit. Photo shows a row of 20 or so rivits in thin brass sheet.

There is also the tool that Gerald Wingrove used which has the punch and die as rollers
Edited By JasonB on 22/03/2022 12:23:40