As described in the title, I would say that it is very safe, but I think you should necessarily use a discus lock. I have ordered my matching castle right from the start and when it is mounted and the castle is drann, it looks very compact and more secure than many of others. Of course there will be no obstacle for professionals, but for wannabe thieves with bolt cutters, I think it is certainly not easy or even impossible to crack it in a short time.