Kuzo zombini ulwakhiwo kunye nosetyenziso lwemizi-mveliso, izikrufu ze-countersunk zifumana ukusetyenziswa okubanzi ngenxa yokukwazi ukugqobhoza umphezulu kunye nokugcina inkangeleko egudileyo. Iimilo ezahlukeneyo zezikrufu ze-countersunk, ezinje ngentyatyambo-emile, imilo enqamlezileyo, eslotyolweyo, kunye nehexagonal, zivumela...
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