Tender For supply of procurement of train fastners d d -hexagonal screw m6x25 , nylon lock nut m6 , prevailing torque type hex lock nuts high type with m16 , socket head screw m5x40 bar 22 , nylon lock nut m5 , hex head bolts partially threaded m16x65 , socket head screw m5x20 , prevailing torque type hex lock nuts all-metal m20 , hex nuts - 0 8d m16 , split spring lock washers with flat end m16