Okay, so I have been doing a ton of research on these bearings the last week. I think the first number I was quoted is completely wrong. I sent pictures off and asked for second and 3rd opinions and got something else.
Being unsure and wanting to know exactly what I need, I decided to research and try to decode them myself.
It appears that last digit on my bearings is really a 5.
I happen to work with a Japanese lady, so I asked her why this last number would look weird since it is like this on both bearing sets. She says the person that was making these just happens to make their 5's that way.
She said when they (Japanese) make a 5. They make it by starting at the top, making the line down, then the curve, then add the top line (across). This explains why the line across the top is offset down the vertical line (just sloppy writing of the person).
Based on this and asking her, she thinks it is definitely a 5.
Based on that and finding an NSK Conversion Data PDF that explains it all I came up with this:
7204 = 47mmOD, 27mm ID, 14mm Wide
A = Contact angle of 30 Degrees
DB = Back to Back arrangement
C9 = Heavy Preload
P5 = ISO 5, ABEC 5
This converts to
7204ATYNDBHP5
or
7204ATRDBHP5
Depending on the cage. I believe no designation (like my part is TR), But TYN seems more common and is better.
So, I am settling on 7204ATYNDBHP5
Before doing all of this, I got another place telling me that NSK came back with this part number
7204ATYNDBHP4
Now, I am not sure if they thought the P5 might be a P4 because of the way it looks in the picture, or if they are recommending a P4 (ISO 4, ABEC 7) because it is better and possibly what they recommend in this application. I have asked, but I have not got the response yet.
I am pretty sure the P4 is a lot more expensive though (double the cost).
Do you guys think I should stick with what my bearing seems to say at P5, or go with what NSK says and a P4???
The P4 part numbers are in the $300's range, but I think the P4, can be had for the $100's range.