Hey After my bike almost getting stolen twice, I decided to test how hard it was to cut locks, chains and cables. I don't have a digital camera so you just have to believe in me.
The tools, 18 inch bolt cutters, a mini hacksaw with several blades made for cutting metal, and a hammer and chisel.
The first lock was a real old master lock 10mm braided steel cable with a master number 3 pad lock. For all the tests I locked my bike to the fence in my back yard, except where noted.
First I used the hacksaw, the cable didnt last long it took about 1.3 minutes to cut through it. Than I took the bolt cutters to the cable and after pinching it one direction than the other direction like an X. I couldn't cut the last couple of strands of cable so I grabbed the cable and kept flexing it back and forth until it snapped.
Conclusion just like everyone says cables are only useful for your seat, I wouldn't even trust my front wheel to one.
Now the master number 3 lock was a joke. The bolt cutters snapped it in an instant but it took a massive amount of force to do it, than I needed to cut the other side of the shackle. The hacksaw cut it in about 5 minutes for both sides, and I needed to change the blade once. I attacked the lock between the laminated plates with the hammer and spike and without a hard surface to back it I couldn't destroy the lock this way.
Next up the thickest chain I could find at the hardware store , it is stamped G3 on the chain. The lock I used on that was a master number 40 diskus padlock. The lock couldn't be cut do to the shackle shroud however, when I took the chain off and attacked the shackle with the bolt cutters it only put light jaw marks on it, it is alot harder metal than the number 3. The hacksaw also was cutting it so slowly it seemed futile. Than I attacked the case of the lock with the hacksaw it was going through it, but not fast enough It would take to long to be usefull method.
Now back to the chain the chain was pretty thick and when I attacked with the bolt cutters, I could put light jaw marks on it, but hanging from the bike I couldn't get enough leverage to snap it. When I layed the chain on concrete and than used the ground as a backstop to attack the lock. With a huge amount of effort I could cut it with the bolt cutters. When I used the hammer and spike I could but big gashes in the chain but it would take to long to break it that way. The hacksaw took about 3 minutes each side of the links and I had to change the blade once.
Conlcusion hardware store chain is pretty crappy as expected, but it would be good for the front wheel or seat however. I did not have any U lock I was willing to sacrifice.
However my previously destroyed on guard beast chain was tested this is a sold secure silver rated lock. The bolt cutters could barely grab the 14 mm chain. And even when backed by concrete I could hardley touch the chain. The theif that tried to cut my chain probly used much larger bolt cutters than I had. The hacksaw blunted instatly when I tried to cut the chain with it. The hammer and spike also did barely anything to the chain. The lock's 16mm shackle I couldn't even grab with the small bolt cutters. The hacksaw barely destroyed the finish. I didn't even bother with the hammer and spike.
Conclusion this lock is tough. I only had one real bike lock on hand to damage but I proved once again that cables are worthless, and hardware store chain is kinda easy to destroy. And Sold Secure silver rated locks cannot be destroyed with tools that fit in a backpack. Except for maybe a battery operated dremel with a couple of cut off wheels. Also assuming you use the U lock correctly and leave no room for a jack. Enjoy