Conventional mechanical anchor bolts are used in construction, including rear counterbore anchor bolts, heavy anchor bolts, anchor anchor bolts and multi-stage expansion bolts. Back reaming anchors are also known as undercut anchors, die reaming anchors and undercut anchors. The biggest difference from other mechanical anchor bolts is that the rear enlarged anchor rod adopts the back anchor technology, and the bottom of the anchor rod is completely embedded to achieve the effect of mechanical locking. The bottom bolt of the rear reaming hole needs to use a special reaming bottom drill bit. Unlike the rear expansion bolts, the multi-stage expansion bolts, heavy-duty bolts and anchor bolts are installed through straight holes, and the installation principle is to form friction with the wall to achieve anchoring.
The anchoring force of the reaming bolt comes from the mechanical locking force formed by the locking key, which is located between the reaming hole at the bottom of the anchor hole and the expansion part of the anchor rod. The anchor bolt is formed by the locking key between the reaming hole at the bottom of the anchor hole and the expansion part of the anchor rod. It is divided into pre-reaming anchor rod and self-reaming anchor rod. Its bearing capacity and tensile capacity are stronger than the other three. The expansion bolt is a kind of bolt formed by extruding the wall of the anchor hole of the expansion part. It is divided into two types: Torque Controlled Expansion Anchor and Displacement Control Expansion Anchor.