Screw kayan aiki ne wanda ke amfani da ka'idodin jiki da lissafi na jirage masu karkata, jujjuyawar madauwari, da juzu'i don ƙara ƙara abubuwa da sassan injina a hankali. Sukullun hakowa da kai shine dunƙule tare da ɗigon rawar bugun kai a bakinsa. Screws wani abu ne na yau da kullun na ɗan adam a cikin tarihi, kuma dangane da aikace-aikacen, ana ɗaukar su ɗaya daga cikin manyan ƙirƙira na ɗan adam.
Sukullun hakowa da kai sabon ƙirƙira ne na baya-bayan nan, wanda kuma ake kira skru mai haƙowa kai. "Screw" kalma ce ta gaba ɗaya don masu ɗaure, ana amfani da ita a cikin maganganun yau da kullun.
Wutsiyar dunƙule mai haƙowa kanta tana da siffa kamar tulun rawar soja ko tulu mai nuni. Ba ya buƙatar sarrafa kayan taimako kuma yana iya yin rawar jiki kai tsaye, taɓawa, da ƙulla kayan da ake girka ko tushe, yana adana lokacin gini sosai. Idan aka kwatanta da sukurori na yau da kullun, irin wannan nau'in dunƙule yana da ƙarfin cirewa da riƙe ƙarfi, yana tabbatar da cewa ba zai sassauta ba ko da bayan dogon amfani. Yana da lafiya don amfani, yayin da aka gama hakowa da buguwa a tafi ɗaya, yin aiki mai sauƙi.
Aikace-aikace: Wani nau'i ne na dunƙule da farko da ake amfani da shi don gyaran gyare-gyaren gyare-gyaren ƙarfe a cikin sassa na karfe, kuma ana iya amfani da shi don gyaran ƙananan ƙarfe a cikin gine-gine masu sauƙi. Ba za a iya amfani da shi don ɗaure ƙarfe-zuwa-ƙarfe ba.
Materials: Akwai shi a cikin ƙarfe da bakin karfe, tare da bakin karfe ya kara kasu kashi daban-daban.
Ayyuka: Φ4.2/ Φ4.8/ Φ5.5/ Φ6.3mm, za a iya yin shawarwari na musamman akan buƙata.
Nau'in tukwici:
Round head (Michelson/Phillips/Torch), Countersunk (lebur shugaban)/Michelson/Phillips/Torch, Hex washer, Round head washer (babban lebur kai), ƙaho shugaban, da dai sauransu.