I saw the M4 size to. I was getting custom hardware and they want exact measurements.Doing some, probably crappy, detective work, the website those pictures are from say they are M4. Judging by some digging I would venture a guess they are M4 x 0.7 10mm. Turner has 18-8 stainless in that size for $1.00 per bolt so thinking you could maybe snag a cheap, zinc plated bolt for a few cents from like a Lowe's or something to try out in the future.