Amabhola ensimbi engagqwali ahlangabezana nezimfuneko zebhola elingaqinile elinokuqina okuhle kakhulu kanye nokumelana nokugqwala. Ukumelana nokugqwala kungase kwandiswe ngokusebenzisa i-annealing. Womabili amabhola angabanjwanga kanye ne-annealed asetshenziswa kakhulu kuma-valve kanye nemishini ehlobene.