... our R&D and QC have 10years of professional experience in this area. it needs to pass 3 inspections before ... )Screw: M4 x 25mm (16 or 20pcs);7)Available in different sizes and surface finishes(SN,GP,PB,CP,NP ... more than 24h 9)Useful life: used in normal after 0.1 million times10)Hinge bearing weights : Thickness 2.5mm: 30 ... bag, 2pcs/box and 100pcs or 50 pairs/carton. Iron door hinge with crown head