Kukho iintlobo ezininzi zezikrufu ezidityanisiweyo, kubandakanywa izikhonkwane ezibini ezidityanisiweyo kunye nezikrufu ezithathu ezidityanisiweyo (iwasha eflethi kunye newasha yasentwasahlobo okanye iwasha eyahlukileyo ecaba kunye newashi yasentwasahlobo) ngokohlobo lwezixhobo ezidityanisiweyo;Ngokohlobo lwentloko, lunokwahlulwa lube yi-pan yokudibanisa intloko ye-screws, i-countersunk head combination screws, i-hexagonal combination screws yangaphandle, njl.Ngokwezinto eziphathekayo, ihlukaniswe ibe yi-carbon steel, insimbi engenasici kunye ne-alloy steel (iBanga le-12.9).