Core Decryption: The Mechanical Principle of Carbon Steel Percussion Anchor Bolts

In key engineering fields such as construction, bridge repair, and equipment installation, the reliability of anchoring is crucial. As an efficient and economical mechanical anchor bolt, the core working principle of Carbon Steel Strike Anchor bolts is clear and has been tested in practice.

Core Mechanism: The Synergy of Mechanical Interlocking and Friction
The core principle of percussion anchor bolts does not rely on chemical bonding, but on pure mechanical interlocking and the huge friction generated to achieve load-bearing. Its working process can be broken down into three key stages:

Insertion and axial alignment: The anchor bolt (usually composed of a main bolt made of high-strength carbon steel and an expansion sleeve or wedge surrounding it) is inserted into a pre-drilled substrate hole (usually concrete, masonry, or stone). The diameter of the hole must strictly match the anchor bolt specifications to ensure that the sleeve fits tightly against the hole wall after the anchor bolt is in place.

Percussion-induced deformation: This is the core action. Use a hammer or other tool to axially percuss the end of the anchor bolt (usually the bolt head or a special percussion head). This impact force drives the expansion element (such as a tapered wedge or a specially designed sleeve) inside the anchor bolt to move downward along the axis of the anchor bolt.

Radial expansion and locking: The downward moving expansion element strongly squeezes the carbon steel expansion sleeve on the outside. The sleeve undergoes controlled plastic deformation (permanent deformation) under strong radial pressure and is forced to expand radially in all directions, thereby:
Mechanical bite: The expanded sleeve material is strongly pressed into the microscopic pores and irregular structures of the substrate hole wall, forming a strong mechanical interlock (similar to a key inserted into a lock cylinder).
Friction constraint: The huge radial pressure generated by the expansion causes extremely high static friction between the outer surface of the sleeve and the hole wall. This friction is one of the main forces resisting the anchor bolt from being pulled out.
Full contact: Expansion ensures that the anchor bolt and the drill hole reach maximum and uniform contact pressure over the entire contact surface.

The key role of carbon steel: the balance between strength and toughness
The choice of high carbon steel as the core material is no accident, it plays an irreplaceable role:
High strength: Carbon steel (usually heat treated, such as quenching and tempering) has a high tensile strength (usually up to 400MPa or more), which can withstand the huge installation percussion force and the tensile and shear loads applied to the anchor during service to prevent the anchor itself from breaking.
Necessary ductility/toughness: At the same time, the material must have sufficient toughness (achieved by precise composition control and heat treatment) to enable it to undergo controllable plastic deformation (expansion) under the action of percussion force, rather than brittle cracking. This balance of toughness and strength is the basis of the reliability of carbon steel percussion anchors.
Wear resistance: Good wear resistance ensures that key components are not prone to excessive wear during percussion installation and friction with the substrate, affecting the load-bearing performance.

The core working principle of carbon steel percussion anchors is essentially to efficiently convert axial percussion kinetic energy into radial expansion mechanical energy and friction constraint energy. Its reliability comes from the strong mechanical interlocking and friction generated by the high-strength and tough carbon steel material during the controlled plastic deformation process. Understanding this clear and direct physical mechanism is crucial for engineers to correctly select, install and evaluate the performance of such anchor bolts. This anchoring, which relies on the material's own strength and deformation ability, provides an efficient and reliable solution in many scenarios.