Product Description
J bolts, also known as 9-shaped anchor bolts, are a type of embedded anchor fastener. One end of the bolt is bent into a "9" shape, which enhances the grip on the concrete and prevents the bolt from being pulled out. Once the hook is embedded in the concrete, it creates a stronger mechanical interlock. Its pull-out resistance and anti-loosening performance far exceed those of 7-shaped anchor bolts, enabling it to withstand greater tensile forces and vibrations.
Product Overview
- Product Name: 9-shaped anchor bolts / J-shaped anchor bolts / Umbrella-head anchor bolts
- Standards: GB/T 799; customizable according to customer drawings
- Common Strength Grades: Grade 4.8 / Grade 5.8 / Grade 8.8
- Common Materials: Q235B (Grade 4.8, General-purpose); Q355B (formerly Q345B, Grade 5.8, High-strength); 45# Steel (Grade 8.8, Heavy-duty)
- Surface Treatment: Natural finish, Electrogalvanized, Hot-dip galvanized (Preferred for outdoor corrosion protection)
- Structural Features: One end features standard metric threads, while the other end has a 9-shaped hook (J-type umbrella handle), designed for embedding in concrete
Product Advantages
- 9-shaped design with exceptional anchoring strength: The hook is shaped like a "9" or "J," providing superior grip when embedded in concrete. Its resistance to pull-out, vibration, and displacement far exceeds that of standard "7"-shaped anchor bolts, making it ideal for heavy-duty, high-load foundations.
- Integrally Forged, Sturdy and Durable: Manufactured by bending solid round steel without any welded joints, ensuring high strength and resistance to breakage for long-term safety and reliability.
- Corrosion and Rust Resistance, Suitable for Harsh Environments: Hot-dip galvanized to resist acids, alkalis, and corrosion, making it suitable for outdoor, coastal, humid, and open-air projects, significantly extending service life.
- Easy Installation and High Versatility: Pre-embedded and cast in a single process; subsequent equipment installation requires only nuts and washers, ensuring high construction efficiency.
- Complete Range of Sizes, Customization Available: Available in sizes from M12 to M48; length, hook size, and thread length can all be customized according to drawings.
Applications
- Steel structure industrial buildings, heavy-duty steel columns, and foundations for overhead cranes and cranes
- Power transmission towers, communication towers, wind turbine towers, and solar panel mounting structures
- Tower cranes, construction elevators, large machine tools, pumps, and fan bases
- Highway guardrails, billboards, streetlights, and bridge anchor bolts
- Infrastructure projects requiring high anchoring and pull-out resistance
Table of Common Dimensions (Based on National Standard GB/T 799) (Unit: mm)
|
Specification d |
Pitch P |
Common thread length |
Reference total hook length |
Common total length L |
|
M12 |
1.75 |
40 |
80–100 |
300–600 |
|
M16 |
2.0 |
50 |
110–130 |
400–800 |
|
M20 |
2.5 |
60 |
140–160 |
500–1000 |
|
M24 |
3.0 |
70 |
160–180 |
600–1200 |
|
M27 |
3.0 |
80 |
180–200 |
700–1500 |
|
M30 |
3.5 |
90 |
200–220 |
800–1500 |
|
M36 |
4.0 |
100 |
240–260 |
1000–2000 |
|
M42 |
4.5 |
120 |
280–300 |
1200–2500 |
|
M48 |
5.0 |
140 |
320–350 |
1500–3000 |
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