What Are The Different Types Of Padlock?

Padlocks come in many shapes and sizes each with their own properties to increase security, make them more convenient to use or protect them from the weather. Here we explain their merits and what makes them ideal for different situations.

Closed Shackle Padlocks

Closed shackle padlocks are designed so that most of the shackle (the U-shaped bar) is shielded by the lock body. This reduces the amount of exposed metal, making it harder to cut with bolt cutters or saws. Many insurance policies require a closed shackle design for high-risk applications. The trade-off is reduced shackle clearance, so always check internal measurements to ensure it fits the hasp, chain, or fitting you plan to lock.

Straight Shackle Padlocks

Straight shackle padlocks are also known as shutter padlocks because they fit neatly onto the locking points of steel roller shutters. However, they are not limited to shutters. Their flat, straight shackle makes them versatile for securing shipping containers, gates, warehouse doors, and storage units. Due to the minimal exposed shackle, they are classed as a form of closed shackle padlock and offer strong resistance to cutting and leverage attacks.

Discus or Circular Padlocks

Discus padlocks use a round, fully enclosed shackle that forms part of the circular body. This design naturally offers closed-shackle protection. The mechanism typically uses a non-spring-loaded locking system, meaning that even if the keyway is damaged, the lock usually remains secure rather than springing open. They are commonly used with hasp and staple fittings, gates, and storage units, especially where bolt-cutter resistance is important.

Long Shackle Padlocks

A long shackle padlock is simply a standard body with an extended shackle to increase reach or flexibility. This makes them convenient for locking around bulkier fittings or multiple loops. However, the longer the shackle, the easier it is to cut, so they should only be used in low to medium security environments. For higher security, choose the shortest shackle length that will still fit your application.

Choosing The Right Type

The best padlock type depends on your environment, risk level, and hardware fitting. Closed shackle and straight shackle designs are best where security is a priority. Discus padlocks are ideal when resisting bolt cutters is important. Long shackle padlocks are most useful where access and flexibility matter more than maximum strength.