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The main choice issues with padlocks are security, corrosion and cost.
- Trivially easy to open without the key
- Good for non-secure access control
- At the bottom of the market, other samples may use the same key as yours
- Little security
- Tough, but rust prone.
- Rustproof, but not so tough
Colour coded padlock
- Straight hasp, C shaped body
Stainless steel shackle
- Harder to cut
- Lightweight lock, low security
- Body made of sheet metal stampings rivetted together.
Cheaper to make than a cast lock
Stainless steel interior
- For use in severe weather
- Hard for a cutting tool to get a good grip on the rounded shape
Heavy duty padlock
- Floor or wall fixing padlock for bike securing
- Some users forget the pass code
- Some users fail to change the pass code
- Slower to use
- Vulnerable to shoulder surfing
Built up shoulders reduce the vulnerablity of the hasp, but have no effect on the more vulnerable parts of the lock
Keyed alike padlocks share the same key pattern. Your batch of keyed alikes will have a different key pattern to someone else's batch.
These padlocks each have their own key pattern, but are also all openable by a master key.
Insurers may require a thatcham approved locks be used for a vehicle, otherwise the insurance policy is invalid.
Padlock security is low as they're easy to open. The main padlock attack modes are lock picking, cutting & shattering. Combination locks are also vulnerable to pass code guessing and dictionary attack.
In many cases the item the padlock is attached to is targeted instead. Standard basic hasps are more vulnerable than a half decent padlock. Using security screws can help to an extent.