Why the most accurate dimension of tubing is essential
If you're working in a machine shop or just tinkering in your garage, you quickly learn that the most accurate dimension of tubing is almost always the outside diameter (OD) because of how these parts are actually manufactured. It's one of those things where theory meets reality, and reality is usually a bit messier than the blueprints suggest. While we'd love for every single measurement—the wall thickness, the inside diameter, and the roundness—to be spot on, the way metal is pulled through a die means the outside surface gets the most attention and the tightest tolerances. ...