Ƙa'idar aiki na nau'i-nau'i masu siffar zobe yana dogara ne akan ƙirar musamman na tsarin su. Ta hanyar haɗin gwiwar hannun riga na waje, hannun riga na ciki, da hada ƙwallo, suna samun daidaito tsakanin nauyi{1}}ƙarar ɗaukar nauyi da sassauci.
A cikin injuna, ana amfani da filaye masu sassauƙa sau da yawa don jure wa hadaddun lodi da motsi, kamar a tsarin dakatar da taya. Suna ba da kaya mai ƙarfi{1}}ƙarfin ɗaukar nauyi yayin da kuma suke jure rawar jiki, gajiya, da tashin hankali.
Bugu da kari, ana amfani da filayen fili mai siffa sosai a cikin tsarin sarrafa injina daban-daban, kamar na'urorin sarrafa injuna da magudanan abin hawa. Tsarin su na ma'ana yana rage rawar jiki da hayaniya yadda ya kamata, yana tabbatar da santsi, kwanciyar hankali, aminci, kuma ingantaccen aikin injina.
