GB / T 3639-}}}}}}}} 2009 governs txias-rub cov khoom sib tw, kom pom tseeb rau cov ntawv thov hydraulic thiab pneumatic:
Qhov seem ntev: ± 0.02mm rau diameters 10-30mm, nrog ncaj tsawg dua los yog sib npaug rau 0.3mm / m kom txo kev sib txhuam.
Nto tas: Ra tsawg dua lossis sib npaug rau 0.8 μm, ua tiav los ntawm ntau-}}}}}}}}}}}}
Mechanical properties: For 20# grade, tensile strength>=450 MPa, yield strength>=250 MPa, and elongation>=10%-ensuring pressure resistance in hydraulic lines.
Kev kuaj: 100% kev kuaj xyuas rau cov tuav loj dua lossis sib npaug nrog kev sim sab hauv, ntxiv rau kev sim siab (10 feeb) {}} nqa cov ntawv thov.
Tus qauv no haum nrog ISO 4394-1 thiab ASTM A108, ua GB / T 3639 tuav haum rau cov thooj voos kheej kheej, precision txiag, thiab pneumatic actuans.