Developed in 1980, the Maxi-Bolt was the first practical undercut anchor. Since that time the Maxi-Bolt has been used in thousands of demanding applications - applications in which a typical sleeve or wedge anchor would have been out of the question. Because of its unique undercut design, the Maxi-Bolt anchor is the functional equivalent of a cast-in-place anchor. Unlike grouted and epoxy anchors, the Maxi-Bolt retains its holding capacity even in cracked concrete. If you have an application involving high design strength requirements, dynamic loading or the possibility of a cracked concrete environment, the Drillco Maxi-Bolt Undercut Anchor is the bolt for you.
Quick Reference Load, Spacing and Torque Tables from ICBO Evaluation Report 4133.
An Undercut hole is the secret of the Maxi-Bolt's superior performance.
Features and advantages of the Maxi-Bolt
Jobsite Photos
Maxi-Bolt installation outline.
Detailed Maxi-Bolt installation procedure.
Detailed Maxi-Bolt installation procedure. Printable version in PDF Format
Animated installation sequence. (610 kB)
The Flush-Mount version of the Maxi-Bolt
Detailed Maxi-Bolt Flush-Mount installation procedure.
Available materials
The Maxi-Bolt is manufactured under a rigorous quality assurance program.
General Design Considerations. Tension and Shear load allowables. ICBO Evaluation Report 4133 Calculating Projected Concrete Area to Determine Concrete Pullout Capacity. Calculating required bolt length when embedment depth and attachment thickness are known. Appendix B of ACI 349, "Steel Embedments" Test Data and Reports
Part Numbering System for Maxi-Bolt Anchors, Drill Bits, Tooling and Accessories