hat
Sa a tib dabitid ki ba teknik egzijans, sèlman yon anwo nan syèl la egzijans osijè de sifas ot tankou 400 sere, 600 sere ak Iwa fini.
eng
This tube usually of low technical requirement,only a high requirement about the ot surface like 400 grit,600 grit and mirror finish.