Feature: Pre-bulbed design requires less installation load. Fastens in Blind Holes with Knurled Body for Anti-Rotation. Specification:Material: Carbon SteelFinish: Color-Zinc-PlatedThread Size: M6x1mmDrill Hole Size (+/-0.1): 9mm/0.35"Total Size: 28 x 16mm/1.1" x 0.63" (L*Max.D)Package Content:10 x Rivet Nuts