... . 4Certificate:ISO9001:2008,SGS Railway Different types of black heavy nuts Details of the product:1Product name: Hex nut, square ... , Zinc plated, Dacron etc.4Proven technique & good quality.5Size range: M6-M426Standard: ANSI, DIN, JIS, AS, BS, UNI, ISO, GB,etc ... .Certificate 2.Various honorary certificates 3.Products Hex nut, square nuts, slotted nut and flange nut. Railway square & hex nuts4.Factory ...