As a last resort, you can find a bolt with a thread that fits, and then take it to Lowes/Home Depot. They have a device (chart with trial threaded holes) that lets you determine thread size, by trial and error. Being Dynaudio, it will likely be in metric.
Recommendation for carpet spikes for Dynaudio Stand 20 speaker stands
I have the Dyn stands for my Buchardt speakers, but lost the supplied carpet spikes. Can anyone help me out with replacements for them? I have posed the question to Dynaudio a couple of times but have gotten no response. Any alternative modestly-priced means of coupling these heavily-weighted stands, filled with lead/sand, would be appreciated. I have Iso-Acoustics GAIA footers under my main speakers, Spatial Audio M5 Triode Master, but prefer a less expensive alternative for the Buchardt's. Thank you.