"Commonly called a jack plane, the No. 5 is the most common plane out there. If a pre-war homeowner bought one plane, it was most likely a jack plane. Why? Well the jack plane can be set up to do almost any job. Camber the iron and it can be a fore plane for removing stock. Set it up with a straight iron or a slightly cambered iron and it can be a shortish jointer plane. It won't work as well as a jointer plane for this, but you can get away with a lot, actually. Set it up with a minutely cambered iron and take a light shaving and you can use the jack as a smoothing plane. Once again, it won't be the end-all smoothing plane, but you'll be surprised what you can do. I know all this because this is how I worked when I had only one bench plane, a vintage No. 5. When people ask me what plane to buy if they only bought one, I usually recommend a No. 5 or its bevel-up equivalent. Now that I own many more planes, I use the No. 5 as a fore plane. With a heavily cambered iron, I use it to dress stock that is too wide for my jointer or planer. With a sharp iron and mild material I can remove almost 1/16" off at a time. It's a powerful, effective and useful tool, even in a shop filled with machines."
Christopher Schwarz is editor of Popular Woodworking and Woodworking Magazine