FAQs
In terms of physical compatibility, both…
In terms of physical compatibility, both T8 and T12 lamps use the same G13 bi-pin base, so as long as they are the same length (e.g. 4-ft), a T8 lamp will physically fit inside a T12 fixture.
As far as safety is concerned,…
As far as safety is concerned, you can exchange them. If you place T12 tubes in a fixture with a T8 ballast, you will wear out the ballast and have to replace it. If you place T8 tubes in a fixture with a T12 ballast, then the tubes will have a shorter life due to a higher current through the tube. Save this answer