L-akbar il-balla tal-azzar, il-diffiċli biex tikseb il-grad ta' preċiżjoni.
Riċentement, KaifengBellStainlessSteelBallManufactureCo, Ltd (BellSTEELBALL) madebatchtrialproductionofØ76.2mmbigsizehighprecisionchromesteelballsandsuccessfullyextendthehighestprecisiongradeofourØ76.2mmlargesizechromesteelballtoG28.Thespecificationsincludevariationofballdiameter, deviationfromsphericalform, surfaceroughness, hardnessandsoontotallysatisfytherequirementsofISO3290-1: 2008, GB / T308.1-2013, ANSI / ABMAStd.10A, DIN5401, JISB1501, ГООТ3722, KSB2001andotherinternationalsteelballstandards.
