Carriage Bolts
Carriage Bolts, also known as coach bolts, feature a smooth, dome-shaped head with a square neck underneath that locks into place when tightened. This unique design prevents rotation during installation, making them ideal for joining wood to wood or wood to metal.
| Parameter | Specification |
|---|---|
Product Type |
Carriage Bolt / Coach Bolt |
Size Range |
M6 – M20 (custom sizes available) |
Material Options |
Stainless Steel, Mild Steel, Carbon Steel, Alloy Steel |
Standards |
DIN 603, ISO, BS, ASTM |
Surface Finish |
Zinc Plated, Hot-dip Galvanized, Nickel Plated, Black Oxide |
Industrial Applications
Carriage Bolts are widely used in:
- Electrical panels and assemblies: Secure fittings where a smooth, tamper-resistant head is beneficial.
- Automotive industry: Used in chassis, body panels, and vehicle frames for vibration-resistant fastening.
- Construction and woodworking: Ideal for timber connections, joists, and heavy-duty wooden structures.
- Furniture manufacturing: Provide a neat appearance for joints while ensuring strong connections.
- Railway, marine, and heavy equipment: Offer strength and reliability in outdoor and load-bearing applications.
Product Description
Carriage Bolts are designed with a round, dome head and a square neck below the head, which prevents the bolt from twisting when tightened through a pre-drilled hole. This feature allows for secure fastening without the need for a holding tool on the head side. Commonly paired with flat washers and nuts, carriage bolts are favored in woodworking, construction, and structural applications due to their high strength and tidy appearance. Available in a variety of lengths, diameters, and finishes, they are suitable for both indoor and outdoor use, including corrosive environments.
Product specifications
- Head Type: Dome-shaped round head with square neck underhead
- Thread Type: Metric ISO coarse thread (standard); UNC/UNF on request
- Size Range: M6 – M20; lengths from 20 mm up to 300 mm (custom options available)
- Material Options: Stainless steel (304/316), mild steel, carbon steel, alloy steel
- Surface Finish: Zinc plated, hot-dip galvanized, nickel plated, black oxide, polished stainless steel
- Square Neck Dimension: Proportional to bolt diameter—prevents rotation during tightening
- Tensile Strength: Up to 800–1000 MPa depending on grade and material
- Shear Strength: ~60% of tensile strength (material-dependent)
- Corrosion Resistance: Excellent when galvanized or in stainless steel grades
- Operating Temperature: -40°C to +300°C depending on material and coating
- Applications: Timber joints, structural frames, machinery, railways, automotive, marine, and furniture
- Standards/Compliance: DIN 603, ISO 8677, BS 4933, ASTM standards
- RoHS/REACH Compliance: Available as per material and finish requirements
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