CNC Machining Tolerances: Standard, Precision and Shop Practice – IsoCNC

What tolerance can a CNC shop actually hold? This IsoCNC reference walks through general machining tolerances by feature and process (milling, turning, drilling, reaming), the step from standard to precision to high-precision work, GD&T callouts that tighten cost, and how to avoid over-tolerancing a drawing. It is written for design engineers and buyers comparing quotes, with the shop practice behind each number. IsoCNC is a precision CNC machining supplier.