... head, Flange head Standard: DIN, BS, AREMA Size: above M16 Raw material: Q235. 35# 45# 40Mn2, 20MnSi.. Our competitive products:Screw ... length limitationLock washers: WL20, WL24, Wl22Flat washer: Uls6, Uls7Nut: Nylon nut, hex nut, square nut, heavy and normal nutShoulders for pandrol type clips