Kat Faz Devlopman nan vis Self frapan

1.Firstase-Ordinarytaintappingscrew la
Itisthedirectproductofearlysheetmetalscrews.Soitalsoknownasthe" sheetmetalscrew" .Itismainlyusedinthesheetmetalchanneltoconnectheatingandventilationsystem.Whenputitintothepreformedhole, makethemetalmaterialsshiftwhichareclosetotheholes, andatthesametimepushthemetalmaterialintothespacebetweenthescrewandthread.Asaresult, itformstheinternalthreadconnectingwithscrews.Thisistheearlist, themostbasicandthemostwidelyusedtappingscrew.
2.Thesecondphase-theselfcuttingtappingscrew
Becausetheordinaryselftappingscrewcanformthethononlyontherelativelythngendepodeboughnesssheetmetalmaterial, licnotbeappliedtothick, di, brittlematerateryal akmaterialwiththepoordeformationability.Thues, anewtypeofcommontappingscrews, theselfcuttingtappingscrewwas sonje.
3.Thethirdphase-theselfthreadingtappingscrew
Apati de lane1950, jeni ak teknolojiponselelekliyevlopevlopadevlopèpwodikas - ansanblajanpwodakoumèt.
4.Tafè-sa-awapwotaj apati
Theabovethreephasesofselftappingscrewhaveonethingoninommuse: itisnecessarytoworkoutprefabricatedholeinadvancennthepittings.Thisisalsotheircommonweakeses.So, intheearly1960s, engineersofspesyalizehavedevelopedtheselfdrillingtappingscrew.Thisisakindoftappingscrewwiththeshapeofdrillattheend.