Biro ka kooban, suunka ayaa inta badan lagama maarmaan u ah in la xiro jeexjeexyada qoto dheer, kuwaas oo aan ku habboonayn tolida caadiga ah. Caadi ahaan waxa ay ka kooban yihiin bir aan bir lahayn ama titanium, waxa kale oo laga samayn karaa agabka sida nikkel, chromium, caag ama bir. Waxa kale oo laga yaabaa inay noqdaan kuwo qalloocan, toosan ama wareeg ah waxaana guud ahaan loo isticmaalaa inta lagu jiro hababka ay tahay in si degdeg ah loo sameeyo, ama meelaha jidhka ah ee ay adag tahay in la tolo. Waxa laga yaabaa in loo isticmaalo caloosha, lugaha, gacmaha, madaxa ama dhabarka.