Good thing for us, the National Center for Explosives Training and Research conducted a padlock breaching test. The study was done to determine the best padlocks for securing stored explosives.
The tests included using a Dremel rotary tool, an oxyacetylene torch, a drill press, a low temperature impact, and compressive cutting jaws to breach the padlock.
Their findings: The best style padlock is a puck style. With this style, the body completely covers the shackle (the locking bar). Puck style locks increase break-in time by almost 13 times compared to a traditional open shackle style lock. Thieves can't access the shackle, so they have to try other methods. The tests showed that even when puck style padlocks had their keyway drilled, they still had to be forced open using additional blunt force.
The highest rated puck style padlocks in their test are the American 2500 and the Abloy Protec2 PL975. While the American 2500 had better results than the Abloy in these tests, the Abloy excels in having better pick-prevention, not part of these tests.
Even though some padlocks may look strong, it does not mean they are strong. The padlock body material makes a huge difference in if the padlock will be breached and how long it will take. The tests found solid, stainless steel provides much more protection than mild steel. The reason is stainless steel will not oxidize when exposed to an oxyacetylene torch, preventing the torch from cutting through.
When buying a padlock, make sure that your trailer has the correct hasp (the part of the trailer door that the padlock locks). The links below have the option to add the correct hasp.
NOTE: The highest rated W-Lok is a shackle style padlock and is NOT recommended to protect tour trailers.
No padlock is completely secure and does not prevent trailer theft, which is why we recommend protecting your trailer with a GPS unit.
(PDF of complete test results at Argonne National Laboratory, Journal of Physical Security.)
NCETR Padlock Test Results
Shackle versus puck style padlocks.
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