Threaded footers for my DIY audio rack

Look at Woodcraft.com or Rockler.com, they have a nice variety of feet, casters, etc.

For the record I do like Herbies gear, using there stuff under my amp and speakers.
If memory serves me correctly they also do very heavy duty versions rated at 200lb plus I think.

Miller.
That is one SERIOUS TT rack.

Were you planning on it still to be standing even if an earthquake leveled your house!
And still playing no doubt... Lol.

Very nice looking piece of kit in all honesty.

Check out Adona, they sell all kind of cones, spikes and footers.  If you have the dough, I would go with the ISO Acoustics GAIA footers.  IMHO, there are no better out there.

lol yeah for a lightweight rack!

Actually since the footer has to attach to the rack a lot depends on your rack construction. Mine for example uses concrete and sand shelves with ABS legs filled with concrete. An end cap screws onto a short length of pipe set into the concrete. Turning the end cap levels the stand. Drilled and threaded you could attach any type of cone you want. Rock solid even under my 800 lb turntable rack.

https://www.theanalogdept.com/images/spp6_pics/C_miller_web/TTstand_1.jpg

But if you're using wood or steel something else might work better. What're you doing?

These are excellent.

https://herbiesaudiolab.com/collections/loudspeaker-rack-decoupling-and-isolation/products/threaded-stud-glider