1. Tightness good 2. Rubbing 3. Environmental protection material 4. Anti-corrosion PTFE extruded rods and bars there are two ... )CallAllowed tolerancecallAllowed toleranceSFBN–14,5,60.481000 50 7,8,90.58 0 10,13,15,161.11000 3.60 SFBN–218 ... ,20,25,301.3 0 35,40,45,501.6 0 55,60,65,702100-300 75,80 ...