2. 1 How many steel bars are used in the rice jar?

12mm. The common rebar sizes are 6 mm, 8 mm, 10 mm, 12 mm and14 mm. The rebar of 12 mm is mainly used to strengthen concrete structures, prestressed concrete structures and foundation works, so the altar edge of 2. 1 m needs1m. Steel bar refers to steel used in reinforced concrete and prestressed reinforced concrete, and its cross section is circular.