Phosphate Surface Finish

[mikewb]

I have successfully used phosphating in the past for mild corrosion protection but now I have a part to phosphate that contains a 32 finish on a seal surface. What surface finish can I expect with Zinc Phosphate? Is Manganese Phosphate going to be different?

Thanks,
Mike

 

[swall]

You have two issues here. The first is the inherent roughness of the crystalline phosphate coating itself. The thicker the coating, the rougher it will be. The other issue is the roughness of the phosphated substrate--I am thinking that at least with a rubber lip seal, this is what you want to look at, as the seal lip will wear its way through the soft phosphate film and ride on the underlying substrate.

 

[unclesyd]

I would contact Birchwood Casey to discuss your problem. I have used the Microlok system to replace phosphating of precision parts.

http://www.birchwoodcasey.com/microlok/index.html