Padlocks are types of portable locks designed to work with a shackle for preventing vandalism, theft, or harm. The history of padlocks can be traced back to the Roman Era when merchants used them to protect their products. Padlocks are designed using hardened materials such as pressed steel, alloy steel, solid brass, and armor encased brass. They can broadly be categorized into four main groups. 1) Discuss style: This group of padlock is designed with a round shackle and does not have angular corners. In most cases, the padlocks are used together with hasps. A staple set is also used to protect the shackle. 2) Shutter lock: These locks are mainly used for protecting external roller shutters
. They are also common in many industrial doors. 3) Conventional style padlocks: These locks are very common in industrial and domestic operations for locking toolboxes, cabinets
, doors, and even gates. 4) Hidden shackle: This category of padlock is designed with a hidden shackle and must be used with a matching hasp. The padlocks have become very common in industrial facilities and transport vehicles because they are very difficult to attack.