I bought all the metal drain pipes to replace a rotted out existing system under kitchen sink . I showed the plumbing supply vendor a picture and shared my knowledge of the set up . He sold me basically exact matching parts ( metal) / I am very handy at most everything except of course plumbing . The pipes he sold me do match up to my existing rotted pieces except of course some shortening i will need to do with hacksaw. Big dilemma is how do you fit 1 1/2 inch pipe into 1 1/2 inch pipe . the same diameter cannot fit into another pipe of the same diameter
First of all I would have used plastic pipes and fittings as they're much easier to install.
However, as long as you have the metal pieces, you can join them with a "Fernco" rubber joint. It is basically a short rubber hose with hose clamps.