Electroless nickel plating used to reduce part variation

[jake53]

Does anyone have experience with the use of electroless nickel plate used to control part thickness?
I have an aluminum spacer which is already electroless nickel plated with thickness held to +\-0.005 mm.
I need to hold this part to +/-0.002 mm. I have seen this done in the past for a bearing bore where parts were sorted by bore size and the plating thickness adjusted to compensate for bore size variation. In that case bore tolerance was reduced from +\- 0.010 mm to +\- 0.005. Does anyone know of someone doing this? What is the best tolerance electroless nickel plating thickness can be held to?

 

[Orange Vise]

It can be done.

Electroless nickel builds up uniformly in a hot bath, unlike electroplating where thickness builds up faster near the electrodes.

You place your part as well as sacrificial part(s) like dowel pins in the same bath. After a certain amount of time (determined through trial and error), you pull a dowel pin and measure the diameter growth to determine plating thickness.

Repeat until you hit your target and then pull the part out.

4 microns is tight but not impossible.

 

[1yesca]

use to see that on motor con rods one end would have copper plating on it

 

[jwmelvin]

... years ago, also used electroless nickel for creating deicing heater circuits on composite nosecones and other surfaces

Thanks for sharing, that’s an interesting process. The circuits look very similar to a 3D printer heated bed.

 

[dian]

there are several types of nickel, varying in hardness, lubricity and many other properties. they get heat treated too. if this is really only
a spacer, maybe look into copper. some solutions will not do more that 5µ. its done cold. if you want to try it youself, its easy. i sometimes do it to e.g. fit a ring on a shaft with tight tolerance. dip it in there, try fit, dip some more, done. its soft.