Underplate for gold - Woods Nickel Strike or Electrolytic Nickel

[deadeye]

We have two very small parts made of .004” Beryllium Copper. They are both chem-etched at a vendor, and then eventually formed onsite. One part is so delicate that it must be plated prior to forming, the other part is plated after forming… not sure why.

They are both plated with 50 microinches soft gold.

One part has an underplate defined as “Woods Nickel Strike”, the other’s underplate is defined as “20 microinches Electrolytic Nickel per AMS-QQ-N-290”.

So my questions are; what’s the difference between these two underplates and does the answer have a bearing on when the parts should be formed?

I am neither a metallurgist nor (obviously) a plating expert so forgive me if I’ve made this unclear.

 

[btrueblood]

Both are electrolytic nickel. Woods Nickel Strike is a particular process/plating bath, whereas the AMS spec. allows, if memory serves, a lot more possible electrolyte solutions.

I've no idea why one would be plated then formed, unless the plating adds strength or lubricating properties to help the forming process. I'd worry about damaging the plating during forming, and so would normally specify plating to occur only after all forming/machining was complete.