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Plating for Wave Soldering Steel and Brass Components

I am a mechanical design engineer with little or no knowledge of plating specs. I need info on the most practical/cost affective plating specs for 2 parts.Both medium / high volume..small PCB components. They are both pressings supplied loose. Both used for power connections via a screw and washer. One part is brass(half hard) The other is steel (CR4)..steel for mechanical reasons. Wave solder process used to assemble to pcb. One industry standard for brass seems to be Tin Over Nickel Is that the best ? and what about Steel. Also what thicknesses ? Hope thats enough info Can anyone advised URGENTLY

Lyndon Shenton
- Stoke-on-Trent, Staffordshire, UK
2000

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I would find it hard to believe that there are not one or more established standards for the items you refer to for the pcb (electronics) industry.

A layer of nickel prevents or retards the migration of copper into the tin which changes its properties significantly. A tin layer will stick to the nickel layer quite well and will wave solder easier than plain nickel.

Tin can be applied directly to steel. We always used a nickel strike under it because it kept the process the same and it seemed to work better.

James Watts
- Navarre, Florida
2000