5 16 18 x 5 16 24 double end stud

Metal expansion nuts, often referred to as expansion anchors or expansion inserts, are specialized fasteners that expand when a bolt or screw is threaded into them. They typically consist of a cylindrical body with slits along its length or an expandable design that facilitates outward expansion. The main purpose of these nuts is to create a secure grip within a substrate, such as concrete, wood, or metal, thereby preventing loosening due to vibrational forces, temperature fluctuations, or stress.


...

In addition to their ease of installation, zinc self-drilling drywall anchors are also incredibly durable and reliable. Made from high-quality zinc material, these anchors are resistant to rust and corrosion, ensuring that they will provide a long-lasting hold for your decorations or fixtures. Whether you're hanging a picture frame, a shelf, or a light fixture, you can trust that these anchors will securely support the weight without any risk of damage or falling.

...