20G m karfe bututu ne na kowa irin sumul karfe bututu. "20G" a cikin sunansa yana wakiltar kayan aikin bututun ƙarfe, kuma "marasa ƙarfi" yana wakiltar tsarin masana'antu. Wannan karfe yawanci yana kunshe da karfen carbon, gami da karfe, da dai sauransu, kuma yana da kyawawan kaddarorin inji da walda. Babban halaye na 20G m karfe bututu ne high zafin jiki juriya, lalata juriya, high matsa lamba ƙarfi, da dai sauransu Saboda haka, shi ne yadu amfani a man fetur, na halitta gas, sinadaran masana'antu, lantarki ikon, yi da sauran filayen.

Matsayin aiwatarwa:
1. Bututun ƙarfe mara ƙarfi don tsari:GB8162-2018
2. M karfe bututu domin isar ruwa: GB8163-2018
3. Sumul karfe bututu for low da matsakaici matsa lamba tukunyar jirgi tube tukunyar jirgi:GB3087-2018
4. Bututu mara nauyi mai ƙarfi don tukunyar jirgi:GB5310-2018
5. High-matsi sumul karfe bututu don taki kayan aiki:GB6479-2018
6. Bututun ƙarfe mara ƙarfi don fashewar mai:GB9948-2018