The International Cessna^® 170 Association

Want to replace the bolt and nuts of my mufflers, pancake style,have them of all colours, which are the correct ones?

Awww. Come on, Fede! You can do better than that. Either look up the part numbers for the exact parts, or use common AN type hardware, preferably with a "C" in the part number indicating anti-corrosive stainless. (Example: AN3-4 is a 3/16" dia. bolt approx. 1/2" long but a AN3C-4 is identical except in stainless.)
Use high-temp lock-nuts such as AN363 or MS21042 all-metal stopnuts. (or AN363C for stainless) You can order hardware from Aircraft spruce. http://www.aircraftspruce.com/

George, now you can see how a person can be addict to this site!!!.
I thought on using AN bolts and nuts, the ones that fit, but since have none of them here, i have to order new a US dealer. I was just looking for types and measures.
Knew you were abouto reply when i see you online at the first page of the forum!!!! THANX!!!

Ha! Yeah, I sometimes need a Cessna 170 Forum "fix" for my addiction too!

Me Three!