Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Tin and Nickel Plating on Stainless Steel 316
Q. We made an assembly in which a small stainless steel (grade 316) plate of 0.8mm thick is press fit into a SS 316 ring (manufactured by precision turning).
For the plate, as per our customers requirement, we carried out nickel plating followed by tin plating giving a total thickness of around 5-7 microns as per standard procedures. But it seems the adhesion of plating is poor even after several attempts of replating.
When a small braid wire (required for the assembly) is tried to be soldered onto this plate, the solder simply comes off along with the plating. Even while trying to press-fit the plate using the fly press, the plating does not withstand the pressure and peels off.
Please advise if there are any specific procedures for obtaining a strong and high quality tin+nickel plating on Stainless Steel. Whether Electroless Nickel Plating will help the process?
Electronic Contract Manufacturer - Chennai, Tamil Nadu, India
2004
A. Hi Vidyasagar. The term 'nickel strike' doesn't appear in your inquiry, so I infer that you are trying to directly plate nickel onto stainless steel, which doesn't work. You will need an acid prep cycle and a nickel strike that are suitable to activate stainless steel. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004
Q. Thanks Ted for the advice. I did find some replies on "Wood's Nickel Strike" to similar enquiries posted on finishing.com. Meanwhile, we also want to try with copper flash before the nickel plating on SS. Do you believe it will help?
The concept of Wood's Nickel Strike is relatively new to us. We wish to understand this process with a more elaborate description of procedure of activating SS through Nickel strike. Kindly help.
Thanks,
Sagar
- Chennai, Tamil Nadu, India
2004
A. No, the copper will not help in my opinion, Vidyasagar Stainless steel almost instantly forms a passive tarnish, and it is not possible to plate with good adhesion onto this passive tarnish. A Wood's Nickel Strike is high in acid and low in nickel content, and what it does is simultaneously dissolves that tarnish while depositing a thin but active (for a short time) nickel coating on it. Immediately after the Wood's nickel strike, you can do a regular electrolytic nickel plating or copper plating or tin plating.
Formulation info, etc., is in most of the plating books listed on our "must-have" booklist. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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Tin Plating onto 430 BA (bright annealed) SS
Q. Hello,
My company recently had a plating problem with one of our products. In the resolution of the issue with our plater, we found through research that our plating specs might be inaccurate.
Current material is 0.016" 430 BA stainless steel that receives a nickel strike and a 100 µinch tin plating. Our end application solders components to the surface of the material.
Through research (ASTM B545), we found that for soldering applications, our tin plating should be at minimum of 200 µinch thickness. My question is, do we need a nickel strike, nickel underplate, and a tin top plate? When is just a nickel strike sufficient? If we need a nickel plate, what should the thickness be? Are there any good plating resources we should know about?
- Zeeland, Michigan, USA
October 26, 2017
A. Hi Isaac. The nickel strike is necessary to gain adhesion onto stainless steel, as described above. After the nickel strike I am not aware of a need to do anything else before tin plating, although we'll see if other readers correct me. The nickel and tin slowly diffuse, so the required thickness of tin plating depends, to some extent, on the desired shelf life of the components. 200 µinch sounds good to me.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 2017
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