External Force Expansion Anchor Bolts

Material: Carbon steel, Stainless steel

These anchors are your go-to for suspending conduit, lighting, and pipe overhead in concrete. All have an internal plug that expands in four directions to create a tight grip before inserting a threaded rod or bolt. Since the grip is focused at the base, these anchors are best suited for concrete, which can handle the gripping pressure better than softer blocks and bricks. They're also known as drop-in anchors.

To install, place the anchor into the hole, insert the required installation tool (sold separately), and drive with a hammer until the shoulder of the tool contacts the anchor. All create a permanent female-threaded connection that lets you remove and reinstall a screw or threaded rod.

Zinc-Plated Steel—The most common choice for areas with occasional exposure to moisture.

Corrosion-Resistant 18-8 Stainless Steel—These anchors resist rust and are the choice for wet and outdoor environments. However, they'll corrode or pit when exposed to salt water and chemicals.

Super-Corrosion-Resistant 316 Stainless Steel—Superior to 18-8 stainless steel, these anchors won't degrade when exposed to harsh weather, salt water, and most chemicals.

Flanged Profile—When your hole is longer than the anchor, the flange prevents the anchor from slipping too far down the hole.