Drop In anchors are concrete anchors with an internal thread designed for anchoring into concrete. Drop the anchor into the pre-drilled hole in the concrete. Using a setting tool expands the anchor within the hole in the concrete.
Internal thread = 6.0mm
Hole drill diameter = 8.0mm
Overall length = 25mm
Drop-in anchors (including ZP / zinc plated variants) are designated by their internal thread diameter, which dictates the size of the bolt or threaded rod they accept.
However, to choose or install one correctly, three distinct measurements must be factored in:
1. Anchor Size (Internal Thread Diameter)The nominal size listed on the box (e.g., M10 or 3/8") always references the internal thread size. A matching bolt or threaded rod must be paired with this size.
2. Outside Diameter (Drill Bit Size)The outer body of the anchor is significantly thicker than the thread. A larger drill bit matching the anchor's Outside Diameter (OD) is required to drill the hole:
Metric Example: An M10 drop-in anchor typically features an outside diameter of 12mm, requiring a 12mm drill bit.
3. Anchor Length (Hole Depth)Drop-in anchors are flush-mount fasteners. The overall length of the metal casing dictates the minimum depth the hole must be drilled
