1/4" Zinc Plated Steel Opened Acorn Push Nuts PSHNL-131 (10 pcs.)

Diameter: 1/4"
Material: Steel
Finish: Zinc
Shape: Opened Acorn
Type: Push Nut

Box of 10.

Instead of threads a push nut uses flanges facing inward acting as teeth to hold it in place. It can be pushed or lightly tapped into place and requires cutting to remove.