New Departure TA Bearings

I need to replace all of the bearings in the taper attachment of my 16CY lathe. The two types of bearings have the following part numbers and dimensions:
- 5201 on inner race, 55501 on metal shield, measures 12mm ID x 32mm OD x 10mm Thick
- 3201 on inner race, 77501 on metal shield, measures 12mm ID x 32mm OD x 15.9mm Thick

The 5201 seems to translate to a 6201 in standard nomenclature, which is a single row ball bearing. The 3201 seems to match the standard nomenclature already for a two row ball bearing.

I saw "77" listed as a code for double shielded in ND nomenclature. Not sure about the "501" or the "55".

I would like to replace these two types of bearings with comparable double sealed bearings but I wanted to understand all of the codes before I make a selection. I am especially curious if there is an ABEC rating that I need to look for. I thought an ABEC 3 would be appropriate for this application.

Can anybody comment if I'm on the right path?

I think you are on the right path. I think "standard" off the shelf bearings will work, I don't think you need an exotic ABEC clearance. If the ID OD and thickness match, then I think you are on the right track. The double shielded could have a little less friction, but even the -2RS versions will not have a lot more...depends on how often you are using the taper attachment. Personally I like to stick to the "better name" bearings, like SKF, NTN, NSK, *********, to name a few, I forget who is actually in business these days, and depend less on names like NICE which are sold at eye poppingly low prices.

DO consider installing SEALED bearings in place of SHIELDED bearings.

Also, DO consider drilling a coolant drain hole, about 1/4" tp 5/16" dia. in each bearing's housing.

Monarch added these to late 10EE taper attachments.

I would just order from VXB for these, you can search their site by dimensions. I've used bearings from them in various places on my EE (taper, gib rollers, belt pulleys...)

Yours translate to 6201 is the 12X32X10 abailable from about $1.30 ea if you buy 10, and go up from there (you can get ABEC 7 for $211 and you can get full ceramic if you want - although no use in this application)
5201 is the 12x32x15.9 these are double row angular contact available for about $13 to 27 ea.

Paul