What is knockout size?
A knockout for 1/2" conduit is 7/8", but the outside diameter of a 1/2" EMT fitting is about 3/4". 3/4" knockout is 1-3/32" (close enough to 1-1/8), and O.D. of 3/4" fitting is roughly 1".Similarly, what is knockout trade size?A knockout for 1/2" conduit is 7/8", but the outside diameter of a 1/2" E...