Decoding hand etched numbers on 7014 angular contact bearings... 1

[pbrubaker]

Hey all,

I'm rebuilding an early 80s machine tool, and the (vertical)spindle uses NSK 7014A bearings. There are some hand etched codes on the outer race of the bearing that I can't find any information on. I want to make sure I know what was in there to begin with before I order replacements. They are DBB arrangement, P4 precision, phenolic cage, and I'm really hoping some of the additional hand etched information can tell me clearance and preload specs.

Lower pair:
7014A DBBP4C8 CH NDH-669C NSK CK-107

Upper pair:
7014A DBBP4C8 CH NDH-669A NSK CJ-57

Hopefully one of you have seen these markings before.

Thanks,

Pete

 

[Tmoose]

ABEC 7 = ISO P4 = "superprecision"

I believe C8 is a "clearance" like C3 etc.
Except it is a preload.

Medium according to page 11 here -

http://www.harshagencies.com/pdf/NSK & RHP Designation Systems.pdf

Note inner and outer spacers must be equal length within 0.0001" or so to keep the preload close to as-manufactured.

 

[pbrubaker]

I can't possibly thank you enough for that link. I have spent hours looking for that.

I knew they were abec7/p4, and I thought C8 might have been clearance as well, but I couldn't find a clearance chart that went above C3. I will make sure the spacers meet the specs on the surface plate before reinstalling (I suspect they do though.)

Thank you very much for your help!