cad-plated stainless steel?

[oilsardine[_2_]]

hi, guys,
I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft
Spruce delivered were some cad-plated rods. I previously got some stainless
and these were silvery-shiny. I complained at AS and they responded that
their stainless 302 pins truely were cad-plated (?) I never heared about
such. What should cad-plating of stainless be good for?

[Blueskies]

"oilsardine" > wrote in message ...
> hi, guys,
> I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft Spruce delivered were some cad-plated rods.
> I previously got some stainless and these were silvery-shiny. I complained at AS and they responded that their
> stainless 302 pins truely were cad-plated (?) I never heared about such. What should cad-plating of stainless be good
> for?
>
>

Hydrogen embrittlement?

[Bob Kuykendall]

> What should cad-plating of stainless be good for?

Beats me. But I've bought .089" wire for MS 20001 and MS 20257 piano
hinges from a couple different suppliers, and all of it had that
yellow-colored plating.

[Charles Vincent]

oilsardine wrote:
> hi, guys,
> I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft
> Spruce delivered were some cad-plated rods. I previously got some stainless
> and these were silvery-shiny. I complained at AS and they responded that
> their stainless 302 pins truely were cad-plated (?) I never heared about
> such. What should cad-plating of stainless be good for?
>
>
Assuming that you are going to attach the hinges with standard cadmium
plated AN hardware, it could be there to prevent the stainless steel
using the cad plated attachment hardware as a sacrificial anode.
Stainless and cadmium fasteners do not necessarily mix well looking at
their relative placements on a galvanic series.

Charles

[El Maximo]

"oilsardine" > wrote in message
...
> hi, guys,
> I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft
> Spruce delivered were some cad-plated rods. I previously got some
> stainless and these were silvery-shiny. I complained at AS and they
> responded that their stainless 302 pins truely were cad-plated (?) I never
> heared about such. What should cad-plating of stainless be good for?
>
>

I work at a place that sells a bunch of stainless and cad-plated parts. I
asked one of the engineers if it was possible to cad-plate stainless steel.

He replied it makes no sense at all. Cad plating is used for corrosion
resistance. Stainless steel is corrosion resistant.

Stick a magnet to the part and see if it sticks. Magnets don't stick to
stainless steel.

[Dan[_2_]]

El Maximo wrote:
> "oilsardine" > wrote in message
> ...
>> hi, guys,
>> I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft
>> Spruce delivered were some cad-plated rods. I previously got some
>> stainless and these were silvery-shiny. I complained at AS and they
>> responded that their stainless 302 pins truely were cad-plated (?) I never
>> heared about such. What should cad-plating of stainless be good for?
>>
>>
>
> I work at a place that sells a bunch of stainless and cad-plated parts. I
> asked one of the engineers if it was possible to cad-plate stainless steel.
>
> He replied it makes no sense at all. Cad plating is used for corrosion
> resistance. Stainless steel is corrosion resistant.
>
> Stick a magnet to the part and see if it sticks. Magnets don't stick to
> stainless steel.
>
>
Some stainless alloys are magnetic.

Dan, U.S. Air Force, retired

[Doug Palmer]

Stainless tends to chew through aluminum pretty quickly (galvinac corrosion)
Perhaps the cad plating is to help protect the aluminum of the hinge
extrusion more so than the stainless.

"oilsardine" > wrote in message
...
> hi, guys,
> I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft
> Spruce delivered were some cad-plated rods. I previously got some
> stainless and these were silvery-shiny. I complained at AS and they
> responded that their stainless 302 pins truely were cad-plated (?) I never
> heared about such. What should cad-plating of stainless be good for?
>
>

[oilsardine[_2_]]

"Dan" > schrieb im Newsbeitrag
...
> El Maximo wrote:
....
>> Stick a magnet to the part and see if it sticks. Magnets don't stick to
>> stainless steel.
small neodym magnet sticks to stainless as well as to steel pins, can't tell
and difference. What is a recommended test for stainless (besids leaving it
outside half a year and watch rusting)?

[Charles Vincent]

oilsardine wrote:
> "Dan" > schrieb im Newsbeitrag
> ...
>> El Maximo wrote:
> ...
>>> Stick a magnet to the part and see if it sticks. Magnets don't stick to
>>> stainless steel.
> small neodym magnet sticks to stainless as well as to steel pins, can't tell
> and difference. What is a recommended test for stainless (besids leaving it
> outside half a year and watch rusting)?
>
>
If a magnet sticks to it, then it is 4xx series stainless I expect. The
traditional homeshop or blacksmith test for various metals is the spark
test, but is not that useful unless you:

A) Frequently perform spark tests and can judge it by eye, which is only
developed by ...........
B) Making up a set of test coupons of various common metals with good
provenance that you can spark test and compare.

There are some tests that can be done with acids, but also take
familiarity, and don't think work as well with the 4xx series.

I think there are perfectly good reasons to cad plate stainless, but you
should verify on your own:

1) Reduce galvanic corrosion when using stainless with aluminum,
magnesium or cadmium plated parts.

2) Cadmium plating acts as a lubricant and will prevent galling which is
a problem with both aluminum and stainless.


Charles

[[email protected]]

On Jun 20, 11:48 am, Dan > wrote:
> El Maximo wrote:
> > "oilsardine" > wrote in message
> ...
> >> hi, guys,
> >> I just ordered some stainless piano-hingepins (pn#03-49000). What Aircraft
> >> Spruce delivered were some cad-plated rods. I previously got some
> >> stainless and these were silvery-shiny. I complained at AS and they
> >> responded that their stainless 302 pins truely were cad-plated (?) I never
> >> heared about such. What should cad-plating of stainless be good for?
>
> > I work at a place that sells a bunch of stainless and cad-plated parts. I
> > asked one of the engineers if it was possible to cad-plate stainless steel.
>
> > He replied it makes no sense at all. Cad plating is used for corrosion
> > resistance. Stainless steel is corrosion resistant.
>
> > Stick a magnet to the part and see if it sticks. Magnets don't stick to
> > stainless steel.
>
> Some stainless alloys are magnetic.
>

Some (or all) of the 400 series are ferromagnetic.
Stainless steel bolts typically are 18-8 (300 series)
and are not. However the 300 series are not heat-treatable
and some of the 400 series are.

Back when I worked in the nuclear industry we used
stainless steel bolts that were cad plated for lubricity.
Sometimes we used some that were silver plated on the
threads only for the same reason. We pretty much
only used 316 SS bolts and nuts.

It is not likely that plating would be done to prevent
hydrogen embrittlement as electroplating is one CAUSE
of hydrogen embrittlement. However, hydrogen diffuses
poorly through nickel so if a bolt were intended for an
environment where hydrogen could diffuse into it, nickel
plating might help. Never heard of that being done--that
part is just speculation.

--

FF