Help with Norton Norax Disk

[Patrice Lemée]

I got some sanding disks I bought a while ago. Some have X100 on them. That I could find is about 220 grit equivalent.
The problem is on the other 2 kind of disks the only writing is “GG 18” for one and “GD 13” for the other. I can't seem to find any equivalent for that.

Anybody knows?

 

[Mike Quesenberry]

No help here, I've never heard of that designation. Have you tried calling Norton?

Good luck

 

[Patrice Lemée]

Haven't called them yet Mike. I am pretty sure I got these from Tracy at US Knife Makers. I see with him first.

Thanks