Circulation pump

[CWR782]

I ordered a circulation water pump OEM P/N 3853850 on ebay from a seller who has good reviews for previous purchases.
The pump wasn't properly packaged and the 2 installation gaskets were torn when I opened the box. Not really a big deal.
I got to looking at the pump and it doesn't have any identification to indicate who it is made by.
From what I have read the backing should be stainless steel which is one of the differences between a automotive marine water pump. The one I received is magnetic.
These things kind of have me wondering if I received an off brand labeled as an OEM?

 

[Scott Danforth]

304 is mildly magnetic

Marine pumps also have brass impellers

 

[CWR782]

304 is mildly magnetic

Marine pumps also have brass impellers

Using the same magnet the original backing plate does not have any pull but the replacement is definitely magnetic.

I used a boroscope and from what I can tell the impeller appears to be brass.

 

[dingbat]

Did they specifically say 304 stainless in the advertising?

304 is Austenitic and should not be magnetic but if there secondary work was done to the parts all bets are off.

The process of stamping and surface polishing can change the micro-structure of S304 and thus create martensite

The stamping die can also leave iron ions on the surface of the material.

Both factors can cause change the non-magnetic properties of the stainless

Annealing the part would transform it back to austenitie.

 

[CWR782]

Here is the description from the listing.

 

[CWR782]

I did look up the company and they are listed as an authorized dealer on the Volvo website.

 

[kenny nunez]

They also came with cast iron impellers look in the large opening, if it is stamped steel then it is automotive.