yes, factories in China copy producrs of some famous brands, however factories must re-design these parts, otherwise they infringe patent.
For magnetics components industry, there are many factories in China, some of factories can supply good products, there are advance manufacture technology and automatic machines and strict quality controling system in factories, however price is maybe higher, when happen quality in customer side, factory can response quickly, however some small factories does not do so.
So I still strong advice you select formal factories, if you will buy mass products from China, please audit factory first, then run small order, until all are smooth, you do not worry about quality and delivery issue and service , you can purchase mass products, I think you are safety if so.