4 1/2" X 5/8"-11 內螺紋心軸，長鉤支撐墊用於不織布美國

The 5/8"-11 female thread fit perfectly on my grinder, and the hook surface holds the non-woven discs secure even under heavy pressure. No slipping at all during use.

The long hook surface grabbed my non-woven disc perfectly and hasn't slipped once during use. Threaded onto my grinder smoothly and feels solid.

Finally found a backup pad that actually stays centered when using hook-and-loop discs. The long hook surface grabs tight and doesn't slip during heavy grinding.