Electrically Insulative Coating for Steel?

[ajensen]

Hi,

I have a small stainless part (think washer, but irregularly shaped) that is about .250" in diameter and between .005" and .010" thick. The part holds a mating piece in position and is designed with fairly tight tolerances (+/- .001" around the profile). I need to electrically insulate this part and am wondering if there is a very thin coating/plating (less than .001") that will do the job. Does anyone have suggestions for a process that might work? Keep in mind the final part dimensions still need to be held to within +/-.001" so whatever coating/plating process is used must be accurate and repeatable enough so that the post-coated/plated dimensions are in spec. The coating/plating does not need to be a super insulator as we are only dealing with less than 4V and less than 600mA.

 

[racookpe1978]

What voltage must be resisted?

0.001 thickness of anything will prevent very, very little voltage. Worse, it can too easily be scratched through, nicked, sliced etc during assembly/re-assembly/repair and lose any resistance.

Make the whole thing of your plastic. As a locator of the next part and not a retainer or bolt or prying point of stress, you'll see only minor pressures that can easily be withstood across such a small distance.

 

[drawoh]

ajensen,

If you need a hard, accurate, non-conductive washer, how about some sort of machinable ceramic?

Ask your machine shop what they like.

JHG

 

[jedward]

paralene is a good insulator but is easily scratched and is usually only about 0.0001" thick

MACOR is an excellent machinable ceramic but would be subject to fracture if subject to any bending - meaning the mating surfaces must be flat