2a thread class right-hand 3.000" thread length 13 thread quantity per inch rubber coated galvanized steel u-bolt with support base per mcmaster carr part number has multiple sources no oem provided rubber fluorocarbon surface treated round bend unc thread series
2b thread class right-hand 3.750" thread length 16 thread quantity per inch work load limit 1090 lbs. has 2 hex nuts & 2 flat washers square bend unc thread series
3a thread class right-hand 1.00" thread length 28 thread quantity per inch u-bolt exhaust duct instl.pegasus F402 adapter assembly round bend unf thread series