Rebar is the common name of hot-rolled ribbed steel bar, and the grade of ordinary hot-rolled steel bar consists of HRB and the minimum yield point of the grade. H, r and b are the initials of the words Hotrolled, Ribbed and Bars, respectively.
Hot rolled ribbed steel bars are divided into three grades: Grade II HRB335 (old brand name 20MnSi), Grade III HRB400 (old brand names 20 mnsi, 20MnSiNb and 20Mnti) and Grade IV HRB500.
I-beam (kg/m)
w = 0.00785×[HD+2t(b–d)+0.6 15(R2–R2)]
H= high
B= leg length
Find the weight of I-beam of 250 mm×118 mm× 10 mm per meter. From the metal material manual, I-beam t is 13, r is10, and r is 5, so the weight per meter is = 0.00785×.
Refer to the above content: Baidu Encyclopedia-Rebar Symbol