tmentBlack oxideSpecificationΦ50*11mmTolerance+/-0.05mm?or according your drawing requestsBrand NameGoldstarCertificateISO9001-2008, ROHS, SGS, CELogisticsUPS, DHL, FedEx, TNTPayment termT/T Main Products Our Service and Advantage Information:1.Surface Treatment Goldstar offers a variety of finishing services for machined parts, including as the?listed table:Black PTEEPassivationWhite ChromeBrushingBlack ChromeHatching knurlingNickel PlatingPlain knurlingElectrolytic Nickel PlatingNitrideWhit