There's levels of deterrence. A lot of thieves will cary bolt cutters that can crop unhardened steel chains easily. I lock my bikes with hardened steel chains b

There's levels of deterrence. A lot of thieves will cary bolt cutters that can crop unhardened steel chains easily. I lock my bikes with hardened steel chains but i have multiple marks on my chain where someone tried to crop the chain. If it was regular steel (or worse, plastic) they would have gotten the bike. If someone really really wants your bike they'll cut through any chain or u lock with a angle grinder but there's a real difference between a Abus chain with 10mm shackles and a $5 chain.