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Large Round Head Carriage Bolt
Large flat head carriage bolts, also known as round head square neck bolts or mushroom head carriage screws, have a large, flat, round head (mushroom head) and a square anti-rotation structure at the neck. The shank uses a full-thread metric machine thread, and the tail is flat. Common sizes range from M6 to M20, and materials include low-carbon steel, medium-carbon steel, alloy steel, and stainless steel. Surface treatments are diverse, including hot-dip galvanizing, electro-galvanizing, Dacromet coating, blackening, and nickel plating. They are widely used in fence connections, steel structure assembly, mechanical equipment fixing, railway bridge engineering, and outdoor facility installation, effectively meeting the connection and fixing needs of different engineering environments.
- Executive Standard
- Specification Range
- Grade & Strength
- Common Materials
- Surface Treatment
- Surface Treatment
- Industry Classification
We support customized production based on customer-provided drawings or industry standards.
Available grades: Carbon steel 4.8/6.8/8.8/10.9/12.9; Stainless steel A2-50, A2-70, A4-70, A4-80
High-quality low-carbon steel, medium-carbon steel, alloy steel, 304 stainless steel, 316 stainless steel, brass, aluminum alloy, etc.
Environmentally friendly blue and white zinc, colored zinc, black zinc, hot-dip galvanized, Dacromet, natural stainless steel, stainless steel passivation
Guardrail connection, steel structure assembly, mechanical equipment fixing, railway bridge engineering, outdoor facility installation
other
Do you need non-standard fasteners, precision metal parts, or custom structural components for a specific application?
Yongji helps you develop and manufacture special parts and custom products based on your drawings, samples, technical requirements, and target application scenarios.
Whether you need prototype quantities, pilot production, or stable mass supply, we provide an integrated solution from engineering review to production and delivery.
From fasteners to structural parts, Yongji offers integrated development and manufacturing for a wide range of custom precision hardware products.
Whether you need a few pieces for validation, small batches for development, or large volumes for mass production, we can support your project at different stages.
With integrated manufacturing resources in China and Vietnam, Yongji helps customers achieve stable quality, scalable production, and reliable delivery.
Yongji Precision Hardware is a global manufacturer specializing in precision fasteners and metal structural components. We are China Large Round Head Carriage Bolt Suppliers and Wholesale Large Round Head Carriage BoltExporter && Company. Founded in 2003, the company has over two decades of experience serving international OEM and ODM customers across multiple industries.
With integrated manufacturing capabilities including cold heading, stamping, CNC machining and sheet metal fabrication...
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