Any of them could work in the right context. What is actually in the garage? At the end, I don't think "the help of" is needed.
Student or Learner
Workpieces/components/parts: which of them suits better in the following context?
It’s forbidden to weld, paint, charge storage battery and do other repair works, as well as clean workpieces/components/parts with the help of flammable liquids in garages and parking places.
Thank you very much. Actually in the text there is no one certain explanation of what works are being doing in the garage or what components it could be. So, I hope, if it's not so important to be explained then i can choose any siutable term)