Drift is a simple and popular tool for drifting ID of casing, tubing, drill pipe and other pipes. It is used to check whether inside diameter of all kinds of pipes are complied with standard, and to determine the max. Inside diameter to be drifted after deformed. The drift is thus granted as necessary tool in workover operation.
DRIFT is the OD measurement or dimension of a mandrel that will pass through a certain piece of tubular. API 5CT specifies particular drift dimensions based on casing size and weight. But it does not seem to clearly state that DRIFT represents an OD dimension rather than an ID dimension. It seems the industry constantly confuses DRIFT for an ID dimension versus an OD dimension.