Making chains or chain links by working the starting material in such a way that integral, i.e. jointless, chains links are formed

Filing statistics

CPC B21L 5/00 belongs to the parent subclass B21L, which recorded 983 patent applications worldwide between 2013 and 2023. Annual filings grew from 58 in 2013 to 58 in 2023 (+0%), peaking at 143 applications in 2018. The most active applicants in class B21 are JFE STEEL (2,667 applications), NIPPON STEEL CORPORATION (2,049 applications) and POSCO (POHANG IRON AND STEEL COMPANY) (1,967 applications).

Source: EPO PATSTAT, worldwide filings