[MrRage]

When someone plans on scraping ways that are chromed plated, the ways are first chrome plated then scraped, is that correct?

[MILLMANM]

never seen it done but chrome is very hard, think it would be ground

[Stevie]

We use diamond compounds to finish hard industrial chrome
We can grind it but we use a special wheel; the wheel is not avail through normal channels

[MrRage]

I guess it would be safe to say that if you were to be building a new bearing surface you would first mill/grind it down, scrape it to a bearing surface, flake the surface for oil retention and then plate the surface to protect it. It sort of makes sense to do it in that order because scraping removes material and plating puts a very small layer of material on the surface.

[mxtras]

The surface is correct and accurate first, then plated. Scraping or "frosting" through the chrome would be a disaster.

Scott

[DareBee]

I agree with the rest, chrome plating is around 70Rc, you will never scrape it. I have never had any trouble grinding chrome though.

[Geof]

My understanding is that hard chroming is used which is different to decorative chrome plating. The parts are finished several thou undersize then plated to a thickness more than the previous undermeasure. After plating they are then ground to the final size leaving a hard chromed surface up to 0.01" thick. A feature of hard chroming is that it crazes; zillions of tiny cracks all over the surface. These act as lubricant reservoirs in the same manner as the scraping marks do on a scraped surface.

[wizard]

Yep like everyone else I have to agree chrome is hard!

Frankly I haven't had a lot of experience with chrome on ways. I did a long time ago work with a guy that was fitting a hydraulic piston to a castiron bore. He had the piston hard chromed & ground. he then lapped the bore to fit the piston. As you can imagine getting the fit right was critical as there where no other seals just a near perfect fit up.

I would imagine that for chrome parts you would do something similar. That is chrome the long ways after they have been properly prepared and then fit the mating saddles.

Thanks
Dave

[tsutt]

I have a wells index that needs to be scraped in a bad way, talked to a local guy who does this for a living, he said no problem scraping thru the chrome with a power scraper and carbide. FWIW. Todd

[Stevie]

yeah; well good luck with that
I have Valve balls hard chromed all the time; if carbide would cut it; I'd save a small fortune in diamond files to remove the whiskers

[tsutt]

yeah, well i put my hand scraper with a carbide edge to the ways and i can cut it. thats all i know. Todd