Nylon Screw In Plastic Spiral Expansion Anchors Self Tapping Drywall Fixing Plugs for Gypsum Board Hollow Wall Product Description The product is a fastener widely used in building decoration, home installation, and light industrial assembly. It is mainly composed of a high-strength nylon expansion tube with external spiral threads and a matching zinc-plated steel screw. The fixing principle is based on a screw-driven expansion mechanism: when the screw is driven into the