This part of ISO 6935 specifies technical requirements for ribbed bars to be used as reinforcement in concrete. This part of ISO 6935 covers ten steel grades not intended for welding which are B300A-R, B300B-R, B300C-R, B300D-R, B400A-R, B400B-R, B400C-R, B500A-R, B500B-R and B500C-R, and eleven steel grades intended for welding which are B300DWR, B350DWR, B400AWR, B400BWR, B400CWR, B400DWR, B420DWR, B500AWR, B500BWR, B500CWR and B500DWR. The steel grades are designated with steel names allocated in accordance with ISO/TS 4949. NOTE The first “B” stands for steel for reinforcing concrete. The next 3 digits represent the specified characteristic value of upper yield strength. The fifth symbol stands for ductility class (4.5). The sixth symbol relates to welding; “-” means not intended for welding and “W” means intended for welding. The last “R” stands for ribbed bar. This part of ISO 6935 covers products delivered in straight lengths. The production process is at the discretion of the manufacturer. Ribbed bars produced from finished products, such as plates and railway rails, are excluded.