1place of origin:Shenzhen Guangdong China(mainland) 2material: iron ,carbon steel,SUS 3size: m2-m12 big head screw1place of origin:Shenzhen Guangdong China(mainland)2material: iron ,carbon steel,SUS3size: m2-m124finish:Zinc,nickel plating5certificate:ISO 9001 2008 RHOS6sample is welcome ,we also receive OEM big head screw