The Flat Head Carriage bolt DIN608-Countersunk Head Square neck Screw GB10, the commonly used standrads are Chinese standard GB10 and DIN608,Infly Fasteners Inc is a manufacturers factory of GB/T 10 Flat head Carriage Bolt, to supply to Countersunk head square neck bolt and Flat head square neck Carriage bolt, we are according to DIN608 GB10 and EN ISO 898. About Flat Head Carriage Bolt DIN608-Countersunk Head Square neck Screw GB10, we can do: Size: diameter:M5-M16, Length: 20-200mm Material: Carbon steel class 4.8-8.8, Q195, 1008, 1035, 10B21 Surface: Self, colour, White zinc, Blue zinc, Yellow Zinc, Black, Hot dip galvanizing Packing: bulk about 20KG-25KG carton and then on pallet.