M24 carbon steel anchor bolts, grade 8.8, 10.9 manufacturer's products metric measurement

M24 carbon steel anchor bolts, grade 8.8, 10.9 manufacturer's products metric measurement

1,Description:

When mechanical components are installed on a concrete foundation, the J-shaped or L-shaped end of this type of bolt is embedded in the concrete for use.

The tensile capacity of anchor bolts is the tensile capacity of the round steel itself. The size is equal to the cross-sectional area multiplied by the allowable stress value (Q235B:140MPa, 16Mn or Q345:170MPA), which is the allowable tensile bearing capacity at the time of design.

Anchor bolts are generally made of Q235 steel, which is smooth and round. Threaded steel (Q345) has high strength, and the threads used to make nuts are not as easy as those made of smooth round steel. For round anchor bolts, the burial depth is generally 25 times their diameter, and then a 90-degree bend hook about 120mm long is made. If the diameter of the bolt is very large (such as 45mm) and the burial depth is too deep, a square plate can be welded at the end of the bolt, that is, a large end will do (but there are certain requirements). Both the burial depth and the bent hook are designed to ensure the friction between the bolt and the foundation, preventing the bolt from being pulled out and damaged.

Anchor bolts can be classified into fixed anchor bolts, movable anchor bolts, expansion anchor bolts and adhesive grounding anchor bolts. Among them, according to different shapes, they are classified as: L-shaped embedded bolts, 9-shaped embedded bolts, U-shaped embedded bolts, welded embedded bolts, and base plate embedded bolts.

2,Applications:

Grade 8.8 bolts represent a high-strength bolt classification within the International Organisation for Standardisation (ISO) and German Industrial Standard (DIN), exhibiting the following notable characteristics:
Strength Properties
Grade 8.8 bolts possess a tensile strength of 800 MPa and a yield strength of 640 MPa. The first figure, 8, denotes a tensile strength of 800 MPa, while the second figure, 8, indicates a yield strength to tensile strength ratio of 0.8. This strength combination makes it one of the most commonly used high-strength bolt grades in industrial applications, offering a favourable balance between strength and cost.
Material and Manufacturing
Grade 8.8 bolts are typically manufactured from medium-carbon steel, with common materials including C35, C45, 35 steel, 45 steel, and other steels with carbon content between 0.30% and 0.50%. The manufacturing process involves hot forging, thread rolling, and heat treatment (quenching and tempering) to achieve the required mechanical properties. Post-heat treatment hardness typically ranges between 22 and 32 on the Rockwell scale.
Mechanical Properties
Grade 8.8 bolts possess high tensile strength and good yield strength, enabling them to withstand significant static and dynamic loads. Their yield-to-tensile strength ratio of 0.8 indicates substantial elastic deformation capacity before reaching yield point, particularly crucial under impact loads. Concurrently, Grade 8.8 bolts exhibit moderate ductility and toughness, with fracture elongation typically no less than 12%, ensuring no sudden brittle fracture under overload.
Application Fields
Grade 8.8 bolts are extensively employed in general machinery manufacturing, steel structure connections, the automotive industry, and mechanical equipment installation. Within steel structures, they are commonly used for secondary connections and general load-bearing frameworks. In automotive applications, they connect engines, chassis, and bodywork. Within mechanical equipment, they secure general-purpose equipment bases and connect pipe flanges. For heavy machinery subjected to intense vibration or impact, higher-grade bolts such as 10.9 or 12.9 are typically required.
Usage Restrictions
Grade 8.8 bolts are unsuitable for extreme low-temperature environments (below -40°C), as medium-carbon steel exhibits significantly reduced toughness at low temperatures, increasing susceptibility to brittle fracture. When used in corrosive environments, appropriate surface protection treatments such as galvanisation, phosphating, or coating are required. Grade 8.8 bolts exhibit poor weldability and are generally not recommended for welding, as the heat-affected zone can cause increased hardness and embrittlement.

Packaging Options

Available in small packing, carton packing, or pallet configurations to meet your shipping and storage requirements.

Manufacturer Information

Manufactured by JIA SHAN Hardware Company with strict quality control measures and pre-shipment inspection.