Iigiya zinokuhlelwa ngokwemilo yezinyo, imilo yegiya, imilo yomgca wezinyo, umphezulu apho amazinyo egiya abekwe khona, kunye nendlela yokuvelisa.
I-1) Iigiya zinokuhlelwa ngokwegophe leprofayili yezinyo, i-angle yoxinzelelo, ukuphakama kwamazinyo kunye nokufuduswa ngokwemilo yezinyo.
2) Iigiya zahlulwe zaba ziigiya zesilinda, iigiya ze-bevel, iigiya ezingezizo ezesetyhula, iirakhi, kunye neegiya zeentshulube ngokwemilo yazo.
3) Iigiya zohlulwe zibe ziigiya ze-spur, iigiya ze-helical, iigiya ze-herringbone, kunye neegiya ezigobileyo ngokwemilo yomgca wezinyo.
I-4) Ngokwesixhobo somphezulu apho amazinyo egiya akhona, yahlulwe kwigiya yangaphandle kunye nesixhobo sangaphakathi.Isangqa sencam yesixhobo sangaphandle sikhulu kunesangqa seengcambu;ngelixa isangqa sencam yesixhobo sangaphakathi sincinci kunesangqa seengcambu.
I-5) Ngokwendlela yokuvelisa, iigiya zohlulwe zibe zizixhobo zokuphosa, ukusika iigiya, iigiya eziqengqelekayo, iigiya ze-sintering, njl.
Ukuhanjiswa kwegiya kwahlulwe ngokwezi ntlobo zilandelayo:
1. Ukuqhuba i-cylindrical gear
2. Bevel gear drive
3. Hypoid gear drive
4. Ukuqhuba i-helical gear
5. Ukuqhuba iintshulube
6. Arc gear drive
7. Cycloidal gear drive
8. Ukuhanjiswa kwegiya yePlanethi (edla ngokusetyenziswa kuthumelo lweplanethi oluqhelekileyo olunezixhobo zelanga, izixhobo zeplanethi, izixhobo zangaphakathi kunye nesithwali seplanethi)