M12 M18 M24 grade 4.8 galvanized J-shaped hook metal bolts Structural steel Metal building

M12 M18 M24 grade 4.8 galvanized J-shaped hook metal bolts Structural steel Metal building

1,Description:

J-bolts (J-type bolts/J-type anchor bolts), also known as umbrella-handle anchor bolts or hook-head bolts, possess the following principal characteristics:
Structural Features
Design: The J-bolt features an 180° hook at its end, resembling the letter ‘J’ or an umbrella handle. This hook section engages with reinforcing bars (rebar) within concrete to form a mechanical lock. Unlike the 90° right angle of L-bolts, the J-type hook provides a larger anchoring contact area.
Performance Characteristics
High Pull-Out Resistance: Due to its unique hook design, the J-bolt achieves superior anchoring performance in concrete. For equivalent specifications, J-bolts typically exhibit 20%-30% greater pull-out resistance than L-bolts. The hook design creates a stronger mechanical interlocking effect, preventing the bolt from being pulled out of the concrete.
High Load Capacity: J-bolts generally possess greater load-bearing capacity, making them suitable for heavy-duty structures subjected to significant loads. Their design enables outstanding resistance to vertical pull-out forces.
Superior Seismic Performance: The hook design demonstrates greater stability under dynamic loads and vibrational conditions such as earthquakes, making it ideal for high-vibration environments including industrial buildings and machinery foundations.

2,Applications:

Features and Advantages
High tensile strength, with the L-shaped right-angle design offering superior pull-out resistance and stability compared to J-bolts.
Excellent shear resistance, as the right-angle configuration provides greater stability against horizontal shear forces.
Installation typically employs the embedded method, incorporated during concrete pouring.
Common materials include Q235, Q345B, and 16Mn steel grades, with 40Cr available for high-strength applications.
Corrosion Protection Surface treatments such as galvanising or hot-dip galvanising are applicable for outdoor environments.

the comparison between German Standard (DIN) and American Standard (ANSI/ASME/ASTM) expressed in text format:

Unit of Measurement

The German Standard uses the metric system with measurements in millimeters (mm). The American Standard uses the imperial system with measurements in inches.

Thread Standard

The German Standard employs metric threads designated as M series (such as M8, M12, M16). The American Standard uses unified threads designated as UNC for coarse threads and UNF for fine threads (such as 1/4-20 UNC).

Thread Angle

Both standards share the same 60-degree thread angle.

Pressure Rating

The German Standard uses the PN series including PN6, PN10, PN16, PN25, and PN40. The American Standard uses the Class series including Class 150, 300, 600, 900, and higher ratings.

Primary Application Regions

The German Standard is primarily applied in Europe and most parts of Asia. The American Standard is primarily applied in North America including the United States and Canada, as well as Latin America.

Standard Organization

The German Standard is established by Deutsches Institut für Normung which translates to German Institute for Standardization. The American Standard is established by the American National Standards Institute (ANSI) and the American Society of Mechanical Engineers (ASME).

Detailed Differences
1. Dimension and Thread Designation
German Standard: M16-2×60 denotes a nominal diameter of 16mm, pitch of 2mm, and length of 60mm
American Standard: 1/4-20×3/4 denotes a nominal diameter of 1/4 inch (approximately 6.35mm), 20 threads per inch, and length of 3/4 inch
Key Differences:
The American standard 10-gauge bolt has a shank diameter of 4.826mm, whereas the equivalent German/Chinese standard M5 has a diameter of exactly 5mm – a difference of 0.174mm, rendering them non-interchangeable.
The American standard 1/2-13 UNC pitch is approximately 1.954mm, while the equivalent German standard M12×1.75 pitch is 1.75mm, indicating differing thread densities.

 

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.