Izikulufu, izakhi zemishini ezibonakala zilula, ziyizingxenye ezibalulekile embonini yesimanje. Ahlanganisa i-shank, inati, nemicu. Ngesakhiwo sazo se-helical esihlakaniphile, ziguqula ukunyakaza okujikelezayo kube ukunyakaza okulandelanayo, ngaleyo ndlela kufinyelele umsebenzi wokubopha noma ukuxhuma.
Umnyombo wesikulufu usentangeni-emseleni ovunguzayo ozungeza umphini. I-engeli yochungechunge inquma ukucinana kwesikulufu, ngemicu emahhadla necolekileyo ivamile. Izintambo ezimahhadla zinikeza amandla aphezulu futhi zifanele ukuthwala imithwalo esindayo, kuyilapho imicu ecolekile inembe kakhudlwana futhi ivame ukusetshenziswa ezintweni ezincane-ezinezindonga noma lapho kudingeka khona ukuxegiswa. Intambo namantongomane asebenza ndawonye ngokungqubuzana nokusebenzelana kwemishini ukuze kuvikeleke izinto, idizayini elula futhi esebenzayo.
Izikulufu ngokuvamile zenziwe ngensimbi (njengensimbi, insimbi engagqwali, ne-aluminium) noma amapulasitiki obunjiniyela. Izikulufu zensimbi ziqinile kodwa zijwayele ukugqwala; izikulufu zensimbi engagqwali ziyagqwala-ziyamelana futhi zifanele ukusetshenziswa ezindaweni ezinomswakama; nezikulufu zepulasitiki azisindi futhi ziyavalela, zivame ukusetshenziswa ezintweni zikagesi. Ukwelapha okungaphezulu okufana ne-zinc plating, i-nickel plating, noma ukwenza mnyama kungathuthukisa ukumelana nokugqwala kwesikulufu.
Naphezu kobukhulu bazo obuncane, izikulufu zihlanganisa umsebenzi omangalisayo wobuhlakani bonjiniyela. Umklamo wabo awubeki phambili ukuqinisa amandla kuphela kodwa futhi ukufakwa kalula. Isibonelo, izikulufo zesokhethi ye-hexagon zivikelekile ngesikrufu, zivimbela ukushelela; -izikulufu zokuzithepha zingajikijelwa zibe izinto ezithambile ngaphandle-ukuzibhoboza ngaphambili; kanye nezikulufu zokunweba, ezinamashubhu azo okunweba, zinikeza ukubamba okuthuthukisiwe, okuzenza zilungele ukulungiswa odongeni lukakhonkolo noma lwezitini.
Izikulufu zitholakala yonke indawo empilweni yansuku zonke kanye nokukhiqizwa kwezimboni-kusuka ekuhlanganisweni kwefenisha kuya emkhathini, kusukela ekulungisweni komakhalekhukhwini kuya ekwakhiweni kwebhuloho. Basebenzisa izakhiwo ezilula ukuze baxazulule izinkinga ezingokoqobo, bebonisa ukuhlakanipha kobunjiniyela "kokusebenzisa ubulula ukuze baqonde ubunkimbinkimbi." Ngokuzayo lapho uqinisa isikulufu, cabangela idizayini enkulu ngemva kwale ngxenye encane.
