You should know and be able to verify all specifications associated with the part you're inspecting. However, it's common practice for things like material certifications from suppliers, work orders from machinists, and other in-line inspections, to have a trail of paperwork signed off by qualified employees. In our company it's required that the QC inspector gather all the paperwork and verify that all the information meets the spec. For example, some of our rubber parts are Mil Spec. As a QC inspector, I can't verify that the rubber meets spec, I'm not a chemist. Our supplier provides CofCs and I just verify that they say they used the right thing. The same goes for in house production. I simply verify the paperwork that the assembly tech signed off on. I can't know for sure that they used the right bonding agents, that would require destructive testing and reverse engineering. All I can do is verify that an employee who is adequately trained signed off that they used the right agent. QC can't do everyone jobs for them.

Not sure this helps at all.