I suggest Grade 8 hardware on anything involving those steps.
After the last rivet break, I sucked it up and replaced all the rivets with grade 8 bolts, washers, and lock nuts.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW