Ibhola lihlukaniswe izigaba ezimbili: uphawu oluthambile noluqinile.Amamodeli yilawa: amabhola anezindlela ezimbili, amabhola amathathu, ibhola eligobile, ibhola eligxilile, njll., namabhola ahlukahlukene angewona ajwayelekile angenziwa ngendlela oyifisayo kubasebenzisi.Izikhala zenziwe ngomgunyathi, zakhiwe futhi zishiselwe ikhoyili.Izinto ezitholakalayo yilezi: 304, 304L, 316, 316L, njll.