M8*30 Big Head Carriage Bolt - Coach Bolt, Round Head Square Neck, HeavyDuty Series, FastenMaster

Big head coach bolt M8x30

M8-30 carriage bolt

Heavy duty carriage bolt M8-30

Big head carriage bolt M8*30

Heavy duty carriage bolt M8-30 with big head design. Also called Big head coach bolt M8x30 or M8-30 carriage bolt. Ideal for construction, machinery, industrial applications. Durable and secure.

Specification

SEODescription

The Big Head Coach Bolt M8x30, also known as M8-30 Carriage Bolt or Heavy Duty Carriage Bolt M8-30, is a robust fastening solution designed for structural applications requiring high load-bearing capacity. Featuring an M8 thread diameter and 30mm shank length, this bolt incorporates a distinctive enlarged domed head for secure surface contact and anti-rotation functionality. Constructed from grade 8.8 carbon steel with hot-dip galvanized coating, it offers corrosion resistance in environments ranging from -20°C to +120°C. The square neck under the head anchors firmly into pre-drilled materials, eliminating spinning during installation. Widely used in construction, heavy machinery, agricultural equipment, and transportation infrastructure, its advantages include exceptional shear strength (up to 20kN) and vibration resistance. Limitations include requirement for precise square-hole alignment and reduced effectiveness in thin materials below 5mm thickness. Compatible with standard M8 nuts and washers, this bolt meets DIN 603/ISO 7380 specifications for industrial fasteners.

SEOSpecification

Parameter	Specification
Product Model	Big head coach bolt M8x30
Alternate Names	M8-30 carriage bolt, Heavy duty carriage bolt M8-30
Thread Size	M8 (8mm diameter)
Length	30mm (underhead measurement)
Head Type	Oversized domed head
Head Diameter	16mm ±0.2mm
Drive Type	Hex socket (internal)
Material	Grade 8.8 carbon steel
Tensile Strength	800 MPa minimum
Surface Treatment	Hot-dip galvanized (50μm)
Thread Pitch	1.25mm (standard coarse)
Shank Length	25mm ±1mm
Torque Capacity	35-40 N·m
Standards Compliance	DIN 603, ISO 4014

SEOQandA

question:Does the company have a professional product selection engineering team?
answer:Yes, we have a dedicated team specializing in market analysis, supplier evaluation, and product quality control.
question:Do you provide technical selection services?
answer:We offer technical support for product selection, including specifications, compatibility checks, and tailored recommendations.
question:Can you provide shipment photos, purchase dates, and info for similar products?
answer:Yes, we can share shipment photos and product details upon request, subject to client confidentiality agreements.

SEOQandA_Product

question:Difficulty installing bolt due to tight fit.
answer:Apply lubricant or slightly enlarge the hole to ease installation.
question:Bolt loosening under vibration.
answer:Use lock washers or thread-locking adhesive to secure the bolt.
question:Corrosion in humid environments.
answer:Opt for stainless steel or galvanized bolts for better resistance.
question:Head rounding during tightening.
answer:Use a correctly sized wrench and avoid over-torquing the bolt.
question:Mismatch with existing thread standards.
answer:Verify thread pitch (e.g., ISO vs. ANSI) before installation.