Bearings

[Ted in NE-OH]

I need a PN 368 bearing, I can find PN 368A, what is the difference?
 

[Bob Huntress]

While I don't even know what brand we are talking, when I saw a letter change at the end of a part number when getting parts from the military supply system using the manufacturer's part number as oppose to a NIN, it usually denoted a change in the part. It usually meant that the original part wasn't right and had been changed. It could be the material was different or something, but the part that was only a number, but now was a number followed by a letter most often A or B was a replacement for the only a number part. I would suggest calling the manufacturer and confirming the change, but that was what it usually meant.
 

[greygoat]

It looks like a Timken part number.
(and, I believe, that all taper roller bearings
use Timkens numbering system)
 

[Jeff B.]

You're probably talking about a Timken number. Typically, the base number (368 in your case) indicates the size and load capacity of the bearing. The letters in the prefix and suffix usually indicate modifications of the original specification. Some changes could be as simple as having a snap ring groove, or the inner bore radiused slightly to fit against the shoulder of a shaft more snugly in very specific applications. Myself being in the auto parts industry for 30 years or more, I wouldn't sweat it. If it looks the same and measures the same it will probably work just fine.