Rebar is used for concrete reinforcement in projects such as foundations, slabs, patios, driveways, sidewalks, curbing.
1/2" diameter = #4 rebar
Deformed rebar refers to the pattern of ridges rolled onto the rebar which helps concrete grip the bar.
Rebar is made of unfinished steel and is susceptible to rusting. Surface rust will not affect the performance of rebar.