I finally got a good phone number for NSK and talked to NSK directly which clarifies a lot of things. Now I am full circle back to the original part number I was quoted.

First of all I confirmed all this DB DF stuff is nonsense and obsolete. They are all pretty much DU(Universal) and they just put DU's together to make a set with the "old" DB, DF, etc. part numbers.

No one is using the 30 degree stuff anymore really, and moving on with 25 degree (A5).

TR vs TYN does not really matter in this case. Buy whatever is available, but the person I talked to would prefer the TR anyway due to better support. Again, either will work in my application fine.

Get the P4Y is pretty much the consensus for them and what they use in their current ball screw support bearing stuff.

Basically, it sounds like they are making a lot of higher quality bearings and then just marking them what they need to be, to be sold LOL.

With all of the information gained in that short phone call, it explained a lot. However, now I am back to the 7204A5TRDUHP4Y and the price tag that comes with them. However they are in stock and are the up to date current part number of things.

The good thing about all of this, is that now I feel comfortable with knowing I am buying the correct thing.

I also talked to an Engineer there and he said the nut should be tightened to 150 in/lb.