I have ran into the OSB on top of the seel top plate. I hole saw the steel with a 1-3/8" then drill the wood with a 3/4" auger bit. Just hole saw enough to remove the steel. We had a lot of this in an eye Dr. office where all the interior walls were steel studs. They ripped 2x4 stock to lay inside studs in every exam room where upper cabinets were to be mounted so they could lag them into wood instead of flimsy steel. Made it impossible to use steel stud bushings. The state inspector suggested I drill the steel with an over-sized hole saw then drill the wood with a smaller auger centered in the opening in the steel. He considered the cable protected by the wood "bushing".
