Nickel-free jewelry is jewelry that is made without any nickel or trace amounts of nickel. Many people suffer from nickel allergy or nickel sensitivity. Hypoallergenic jewelry means that there is minimal risk of causing an allergic reaction.
When looking for findings, or chains it is best to find some that are safe for the customers. Many customer have many allergies and keeping that in mind when shopping or making your pieces will help you pinpoint wholesalers and craft stores to use.
I wasted a lot of money on findings and chains that weren't nickel free or hypo-allergenic. Now that I did my research, I now ask question regarding the material that I buy. It is a hard lesson to learn financial but the lesson is worth learning.