Maxi-Bolt Installation Outline

Contractors who have never installed the Maxi-Bolt are often concerned that the installation process will be overly complicated and time-consuming. Feedback from contractors who have used the product, however, is to the contrary.

As compared to a typical wedge or sleeve anchor installation, there is only one extra step - undercutting the hole in concrete. Typically this step takes 30 to 60 seconds and is more than offset by the fact that the Maxi-Bolt has a zero rejection rate. Wedge and sleeve anchors often fail to set properly because they slip too far out of the hole as they are being torqued. They must then be reworked or replaced. It is this sort of uncertainty which really upsets contractors. With the Maxi-Bolt, the contractor knows that once it's in - it's in for good and will pass inspection.

As compared to grouted and epoxy type anchors, the Maxi-Bolt offers a clean installation process which does not require extreme measures to be taken in cleaning and preparing the hole. Since there is no cure time with Maxi-Bolts, the contractor may complete the installation process at the time of anchor installation without having to return to the location. This saves time and money.

The Maxi-Bolt is installed in five steps:

1. A hole is drilled in concrete with a carbide bit, Drillco Rebar Eater bit, or diamond drill bit.
2. The hole is undercut using a Drillco undercutting tool.
3. The hole is cleaned of concrete dust and debris using appropriate means such as a brush, oil-free compressed air or by vacuuming.
4. The anchor is set by drawing the stud and conical nut inside the expansion sleeve forcing the expansion sleeve to expand laterally into the undercut portion of the hole.
5. The material to be fastened is located and the stud tensioned.

Tables in the Detailed Installation Procedure list drill and undercutting tool dimensions and tolerances. The undercutting tool is designed to produce a fixed angle cut in the concrete which matches the angle formed on the anchor's conical nut. Figures 1 and 1A in the Installation Procedure show how the cutter blade opening (Dimension B) is measured. A proper undercut is made when Pin D is at the bottom of Slot E as noted in the Figures.

Steps 4 and 5 above serve to proof load the anchor and to minimize anchor deflections upon loading of the attachment. After installation, measurement of the stud projection beyond the concrete may be used to provide additional verification that the conical nut is properly seated in the undercut portion of the hole. Stud projection from the concrete surface or from the surface of the attachment where the sleeve is allowed to extend through the hole in the plate, equals the overall length of the stud minus the combined lengths of the anchor distance tube and expansion sleeve (see Figure 2. of the Detailed Installation Procedure) with a tolerance of -1/4 inch or +1/2 inch on the measured projections.


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