Abstract: Method and means for maintaining uniform thickness and profile of a metal strip during hot rolling in a multi-stand hot rolling mill, comprising a two-position looper located between adjacent mill stands and movable between a strip threading position above the rolling pass line of the mill and a rolling position substantially in the plane of the rolling pass line, and a thickness and profile gage movable out of operative relationship with the looper when the looper is in a threading position and into operative relationship with the looper when the looper is in a rolling position, the gage adapted to project a measuring X-ray beam from the thickness and profile gage onto the strip during rolling and at an angle to the strip of substantially 90.degree., thereby minimizing measurement error due to variable angularity between the X-ray beam and the strip during rolling.