Round head square neck bolts, commonly known as carriage bolts or coach bolts, are a fundamental and versatile category of fasteners designed for secure and efficient assembly. Characterized by a smooth, rounded head and a distinctive square section directly beneath the head, these bolts are engineered to prevent rotation during tightening, ensuring a stable and permanent connection 68.
Product Overview & Key Features
- Design & Functionality: The primary design feature is the square neck, which embeds into the material (typically wood or a pre-drilled square hole in metal) as the nut is tightened. This action locks the bolt in place, preventing it from spinning and allowing for one-sided installation with common tools 36.
- Head Styles: Available in variations such as small button head (GB/T 12), large button head (GB/T 14, DIN 603), and low square neck designs to suit different aesthetic and functional requirements 34.
- Material & Grades: Manufactured from various materials including carbon steel, alloy steel, and stainless steel. High-strength versions, such as Grade 10.9, are available for demanding structural applications requiring superior tensile strength and reliability 35.
- Surface Treatments: Options include galvanization, zinc plating, and other coatings to enhance corrosion resistance and durability for both indoor and outdoor use 5.
Compliance & Standards
Our round head square neck bolts are produced in compliance with major international standards to guarantee interchangeability, quality, and performance. These standards include:
- Chinese National Standards: GB/T 12, GB/T 14, GB/T 801 34.
- German Standard: DIN 603 34.
- International Standards: ISO 898-1, ASTM A193, and others serve as key references for mechanical properties and material specifications 3.
Primary Applications
These bolts are indispensable across a wide range of industries due to their locking feature and robust construction:
- Construction & Decoration: Widely used in structural connections, dry-hanging stone (e.g., marble) installations, and architectural metalwork 3.
- Transportation Manufacturing: Commonly employed in automotive chassis, railcar assembly, and trailer construction 3.
- Heavy Machinery & Equipment: Essential for assembling agricultural machinery, industrial equipment, and material handling systems where vibration resistance is critical 3.
- Infrastructure & Bridge Engineering: Used in various non-critical structural connections and fixtures 3.
- General Woodworking & Furniture: The standard fastener for securing wood to wood or wood to metal, prevalent in decking, fencing, and furniture assembly.
Post time: 2026-04-10 11:37:31
