[XK120DHC]

In the subject of this post I wrote "query" as opposed to "question".. simply, because I know the amp requirement to zinc plate steel..
My "query" deals with "batch plating" a "pile" of nuts and washers..
Anyone involved in restoring a car or motorcycle has probably run into the "minor" problem that not all the nuts and washers, etc. are exactly the same size.. and especially those of us involved in electroplating parts where amps per square inch can be somewhat "critical" at least, and "picky" at most..
I'm dealing with a 50+ year old British car (that right there says I'm nuts!) and being "typically anal-retentive" about this vehicle, am in the process of calculating the surface area of every individual item I plan on Zinc Plating (I have the "old kit") and Black Chromating. My problem is, I have a small number of nuts and washers whose ASI differs by five to ten milliamps per piece and I just don't know if this minor, almost negligible amount will have an effect on the quality of the plate.
I might add that I have built my own small Barrel Plater (5"dia) just to handle these hundreds of washers, etc. (some washers only have an outside diameter of 1/8th inch).
Additionally, as an example, I have a small bunch of "2BA" nuts that calculate out to 30ma, 32ma and 36ma per piece.. there are 1, 4 and 2 pieces of each respectively.. (I also have some 3BA and 4BA washers that require 14ma and 18ma I need to "combine" with other items, as well) I would hate to have to plate each of these items individually (not to mention trying to regulate such a small amount of amps) if I could combine these pieces (along with others that are "close" in size), this would save a great deal of time..
So, the "query" is: What, if any, is the "allowable" milliamp difference (percentage?) that is acceptable and still achieve a quality plate?
Any and all help appreciated.
Thanks