Inquiry for samples. Order with big quantities will follow HEXAGON HEAD SCREWS UNI 5739 12X40 F 55 SUPER DUPLEX 10 PCS. FLAT WASHERS UNI 6592 12 F55 SUPER DUPLEX 10 PCS. HEXAGON HEAD SCREWS UNI 5739 20X 140 F 55 SUPER DUPLEX 10 PCS. FLAT WASHERS UNI 6592 20 F55 SUPER DUPLEX 10 PCS. HEXAGON HEAD SCREWS UNI 5737 27X185 F55 SUPER DUPLEX 25 PCS. HEXAGON NUTS UNI 5588 M 27X3 PG F55 SUPER DUPLEX 25 PCS. FLAT WASHERS UNI 6592 27 F55 SUPER DUPLEX 25 PCS. HEXAGON HEAD SCREWS UNI 5737 27X180 F55 SUPER DUPLEX 20 PCS. HEXAGON NUTS UNI 5588 M 27X3 PG F55 SUPER DUPLEX 20 PCS. FLAT WASHERS UNI 6592 27 F55 SUPER DUPLEX 20 PCS. Please include material certificates