Amabhola ensimbi engagqwali ahlangabezana nezidingo zebhola elingaqinisiwe elinokuqina okuhle kakhulu kanye nokumelana nokugqwala. Ukumelana nokugqwala kungandiswa ngokufaka i-annealing. Womabili amabhola angagqwali kanye nalawo angagqwali asetshenziswa kabanzi kuma-valve kanye nemishini ehlobene nawo.
