What are the advantages and disadvantages of machine screw anchor compared with expansion anchor bolts

In the field of building construction and equipment fixing, the choice of anchoring technology directly affects the safety and service life of the structure. Machine screw anchors and expansion anchors are two common anchoring products, each with unique performance advantages and application limitations. A deep understanding of their advantages and disadvantages is of great reference value for engineering designers, construction units and purchasers.

Advantages of machine screw anchors
Easy installation and flexible operation
Machine screw anchors usually adopt prefabricated threads and anchor body design. When installing, you only need to drill holes on the substrate, insert the anchor body and screw in the machine screws. No special tools are required during the operation, which reduces the difficulty and time of construction, and is especially suitable for rapid installation on site.
Strong repeated disassembly ability
The structure of the machine screw anchor allows the screws to be partially disassembled and replaced, which is convenient for equipment maintenance and adjustment. For mechanical equipment that needs to be frequently disassembled and assembled, machine screw anchors provide an ideal solution.
Wide range of applications
Machine screw anchors are suitable for a variety of substrates, including concrete, masonry and hollow walls, etc., with strong compatibility and can meet the needs of different engineering environments.
Stable load performance
Due to the threaded fastening mechanism, machine screw anchors can maintain good stability under shear and tension, especially in low-vibration environments.

Disadvantages of machine screw anchors
High requirements for hole accuracy
Machine screw anchors have high requirements for the accuracy of drilling size and depth, and hole diameter deviation may cause the anchor to loosen or reduce the bearing capacity.
Limited corrosion resistance
Standard machine screw anchors are mostly made of ordinary steel. If they are not treated with anti-corrosion, they are prone to rust in a humid or corrosive environment for a long time, affecting the safety of the structure.
Relatively low bearing limit
Compared with expansion anchors, the bearing capacity of machine screw anchors under high load conditions is slightly insufficient and it is difficult to meet extreme load requirements.

Advantages of expansion anchors
High bearing capacity
Expansion anchors expand in the hole through the anchor body and are closely combined with the base material to form a strong mechanical locking effect. They are particularly suitable for withstanding large tensile and shear forces and are suitable for high-strength structural fixation.
Stable fastening effect after installation
After installation, the expansion anchor bolt expands and compresses the hole wall of the substrate through the anchor body. It has strong locking force and is not easy to loosen, ensuring safety and stability in long-term use.
Excellent corrosion resistance
High-quality expansion anchor bolts are mostly made of stainless steel or galvanized, with good corrosion resistance, suitable for outdoor and humid environment applications.
Loose tolerance for holes
Expansion anchor bolts have relatively loose tolerance for drilling hole size, and the requirements for hole diameter and hole depth during installation are not as strict as those for mechanical screw anchor bolts, which reduces the difficulty of construction.

Disadvantages of expansion anchor bolts
Difficult to disassemble
After installation, the expansion anchor bolt expands and locks, and the disassembly process is complicated, often requiring the destruction of the substrate or the anchor bolt body, and inconvenient maintenance and adjustment.
High construction requirements
Precise expansion operation is required during the installation of expansion anchor bolts, and construction personnel need to have certain skills. The installation quality has a greater impact on the anchoring effect.
Relatively high price
The manufacturing cost of high-quality expansion anchor bolts is higher than that of mechanical screw anchor bolts, and the procurement cost and overall project budget may increase accordingly.

Application scenario comparison
Mechanical screw anchors are suitable for medium and low loads, where frequent disassembly or adjustment is required, such as light equipment installation, building interior decoration, and light fixation. Their flexibility and ease of operation meet the needs of rapid construction.
Expansion anchors are more suitable for high-load, high-safety fixing tasks, such as bridge support, heavy machinery and equipment fixing, outdoor structure anchoring, etc. They can effectively resist strong tensile and shear forces to ensure long-term stability.