The Rebco Drift is a precision-machined go/no-go gauge tool used to verify that a specific bore, nipple, or completion restriction will pass a tool of a known minimum OD. Unlike the Gauge Cutter, which cleans and scrapes the bore as it passes, the Drift is a smooth-OD tool manufactured to exactly the minimum drift diameter required. If the drift passes through the restriction without resistance, the bore is confirmed clear for the intended tool. If the drift does not pass, the bore is below the minimum dimension and remediation is required before the planned tool can be run. Drifts are available in a range of ODs to match all standard nipple bore specifications, subsurface safety valve bore dimensions, and custom completion requirements.