What are rear expanded mechanical anchor bolts?

Post-expansion anchor bolts refer to the process of drilling a straight hole on the concrete substrate and then expanding the hole again at the bottom of the hole. The cavity after expansion forms an interlocking mechanism with the open key of the anchor bolt to achieve post-anchor connection.

Post-expansion mechanical anchor bolts are composed of screws, bellows sleeves, flat washers, spring washers, nuts, and are made of 5.8 grade steel, 8.8 grade steel, 304 (A2-70)/316 (A4-80) stainless steel and other materials. The surface treatment is electroplating zinc (average zinc layer thickness > 5 μm), suitable for common environments; hot-dip galvanizing (average zinc layer thickness > 45 μm), used in corrosive environments.

Post-expansion mechanical anchor bolts are used on substrates such as non-cracked concrete/cracked concrete, natural stone, etc., to fix high-load structural parts or install heavy equipment. Post-expansion mechanical anchor bolts have stable and excellent anchoring performance under high loads, vibration loads and impact loads. After the mechanical lock is installed in place, there is no need to wait for curing time, which improves construction efficiency.

The operating procedures of the rear bottom expansion mechanical anchor bolt are as follows: first use a straight hole drill to drill a hole of corresponding diameter and depth, then use a special bottom expansion drill to shake the bottom to expand the bottom into a wedge-shaped hole, then use a soot blower to align the hole until no dust overflows from the hole, and finally knock the rear bottom expansion anchor bolt to expand the bottom and complete the anchoring.