Most stove pipe has one end that has been crimped to a slightly smaller size than the other. The crimped end with the wrinkles slips inside the end with no wrinkles. Put a little petroleum jelly on the wrinkles if it doesn't fit easily.
If you have to cut it, cut the end with no wrinkles. A piece with no wrinkles on either end is useless.
Answered Aug 08, 2012
Edited Aug 08, 2012