(405) Choosing a High Security Lock

Spend some time on bosnianbill's Youtube channel and you'll definitely get some tips. In particular, I'd recommend these videos: Buying Security: link Choosing a high Security Lock: this video (Be ware of about 2 minutes 30 seconds of sarcasm in the last one!) Otherwise, browse through the rest of his videos, skipping the challenge locks unless it's something that fascinates you: link Essentially, cheap locks can be bypassed very easily (almost anything by Masterlock). More expensive locks ($60+) will have more pins, making them harder to pick, and often have replaceable cores. Of course, security isn't just about the lock, which is addressed in the first video. Hope this gives you a starting point!

The top of the line in padlocks is the Sargent & Greenleaf 951 padlock, which is about $1300.[1] DoD uses these on weapons storage. Resists grinders, saws, liquid nitrogen, etc. Here's an amusing overview of available padlocks, starting with crap Master Locks and moving upward.[1] The ones that are hard to force or cut have large-diameter shackles, which probably won't fit a gym locker. [1] this video

Some locks with open designs are difficult, or impossible to pick. In this amusing video this guy goes over details of different locks, and explains why they are not all created equal. this video