10 less than three rebar refers to the rebar?
Grade steel HPB235, grade three steel, HRB400. Where P represents light circle, and R indicates rib (thread).Numbers indicate the degree of flexion (which can be regarded as strength). Is that clear?
A grade steel is round, without ribs, elongation is the advantage, of course, it also determines its strength is lower than grade three steel.
Because of the mechanical properties, three grade steel buckling point is higher, in order to increase the concrete and steel reinforcement force, so add rib (add thread)
