Tools, Sharpening and Power Machinery - Angle grinder spindle nut.

Hi all, I use several die grinders and angle grinders with 4" cutter disks for wood carving. When you buy Arbor Tech disk's they come with a nylon washer type adapter that reduces from 7/8 (size of disk hole) to 5/8(size of Grinder shafts) but I dont like them. (one, its just an adapter washer, two, its nylon with a metal disk spinning at 11,000RPM - NOT) I would rather have somthing like a hex flange nut of 5/8" -11TPI with a central recessed 7/8 bottom to fit in the disk. King arthor sells somthing similar but I dont think it has the recessed bottom to hold the disk. I have one, but had for years and no idea where I got it from. I've checked online industral sites but cannot find one. All replacement angle grinder nuts are not hex, they have the 2 holes, which I am using those also for now, just wanted to put a bug in y'alls ears to see if anyone knew where I can get a few. BTW- King Arthor wants 9.99 apiece for a 1 dollar nut. Any ideas??
Mud.