M6*70 Big Head Carriage Bolt - Coach Bolt, Stainless Steel Heavy Duty Hex Flange Nut

Big head carriage bolt

M6x70 carriage bolt

Heavy duty coach bolt

Big head carriage bolt M6*70

Big head carriage bolt, M6x70 heavy duty coach bolt with large domed head and square neck for secure fastening in construction, machinery, and industrial applications. Durable, corrosion-resistant finish.

Specification

SEODescription

The Big head carriage bolt, specifically the M6x70 carriage bolt, is a heavy-duty coach bolt designed for robust structural connections in construction, machinery, and industrial equipment. Featuring a 6mm diameter and 70mm length with a smooth domed head and square neck to prevent rotation during installation, it typically operates in environments ranging from -40°C to 120°C. Constructed from grade 8.8 carbon steel or stainless steel (A2/A4), it offers tensile strengths up to 800 MPa. Surface treatments include hot-dip galvanizing or Dacromet coating for corrosion resistance. This heavy-duty coach bolt directly interfaces with pre-drilled modules in steel frameworks, timber structures, or concrete anchors. Key advantages include high shear resistance and vibration-proof design, though its non-threaded shank section requires precise alignment and pre-tapped holes. Compliant with DIN 603 and ISO 10642 standards.

SEOSpecification

Parameter	Specification
Product Type	Big Head Carriage Bolt
Thread Size	M6 (6mm diameter)
Shank Length	70mm (underhead measurement)
Head Style	Domed Round Head with Square Neck
Material Grade	Carbon Steel Class 8.8 / Stainless Steel A2
Surface Treatment	Zinc Plated (5-8μm) or Hot Dip Galvanized
Square Neck Dimensions	4.5mm height × 9mm width
Thread Length	30mm (partial threading)
Torque Capacity	12-15 Nm (lubricated condition)
Tensile Strength	800 MPa (Class 8.8)
Standards Compliance	DIN 603, ISO 10509, ASME B18.5
Application Temperature	-50°C to +300°C (material dependent)
Corrosion Resistance	Salt Spray Test: 500-1000hrs (zinc coating)
Drive Type	Square Neck Anti-Rotation Design
Package Quantity	100pcs/box (bulk packaging available)

SEOQandA

question:What is the warranty?
answer:Our products typically include a 12-month warranty covering manufacturing defects, starting from the delivery date.
question:Can you provide shipment photos or purchase records of similar products?
answer:Yes, shipment photos and order details can be shared via email upon request after confirming cooperation.
question:Can the company ensure stable supply?
answer:We maintain reliable inventory and long-term supplier partnerships to guarantee consistent product availability.

SEOQandA_Product

question:The round head rotates during installation, preventing tightening.
answer:Use a serrated flange bolt or hex head carriage bolt for better grip.
question:Corrosion occurs in humid environments.
answer:Opt for stainless steel or galvanized coating to resist corrosion.
question:Insufficient thread length for proper engagement.
answer:Verify application requirements; use custom lengths if standard 70mm is unsuitable.
question:Bolt loosens under vibration over time.
answer:Apply thread-locking adhesive or use a lock washer to maintain tension.
question:Threads get damaged during installation.
answer:Ensure proper alignment and use lubrication to reduce friction during threading.