# 8945 Dunbier High-Tensile Bolt 5/8 x 9" Black | Marine Trailer Part

🔧 Product Description

  

Dunbier Black High-Tensile Bolt 5/8" × 9" - Part Number: 8945

  

A replacement 5/8" × 9" trailer fastener supplied in a black-finished high-tensile steel configuration. It is intended for long high-load Dunbier trailer pivots, supports or structural assemblies specifying part 8945 and should only replace hardware with the same dimensional, thread and strength specification.

  

⚙️ Key Features

  

• 5/8" fastener diameter

• Nominal length: 9"

• black-finished high-tensile steel finish/material

• Hex-head trailer fastener

• Suitable for marine trailer servicing when matched to the original installation

  

📏 Specifications

  

• Diameter/thread: 5/8"

• Nominal length: 9"

• Thread form: imperial thread matching the original Dunbier structural application

• Strength requirement: high-tensile; confirm grade markings on the bolt head

• Finish/material: black-finished high-tensile steel

• Nut and washers are not included

• Black finish provides less marine corrosion protection than galvanising and requires inspection/protection

  

🔄 Cross Reference & Related Parts

  

• Dunbier: 8945

• A generic replacement is acceptable only when diameter, length, thread pitch, strength grade, finish and shank configuration all match

• Do not substitute lower-grade hardware or an unverified stainless bolt in a high-tensile structural application

  

🚤 Trailer Compatibility & Application

  

• Suitable for long high-load Dunbier trailer pivots, supports or structural assemblies specifying part 8945

• Measure the original bolt from beneath the head to the end of the thread unless the fastener standard states otherwise

• The unthreaded grip length must suit the clamped joint and must not bottom the nut before the components are secure

• Use the correct washer, locking nut or spring washer for the original joint

  

🔌 Function

  

Clamps the associated trailer components together and transfers shear, tension and vibration loads through the mounting joint.

  

Common signs of wear or replacement:

  

• Thread is stretched, crossed, stripped or heavily corroded

• Bolt shank is bent, necked, grooved or worn

• Hex head is rounded or cracked

• Joint repeatedly loosens despite correct torque and locking hardware

• Corrosion has materially reduced the fastener diameter

  

🛠️ Installation & Safety

  

• Confirm the replacement grade from the original bolt head and trailer parts documentation

• Do not reuse a fastener that has stretched, yielded or suffered severe corrosion

• Tighten to the specification for the exact bolt grade, thread, finish and joint

• Use corrosion-compatible washers and locking hardware

• Recheck critical trailer fasteners after the first trip and during routine servicing

  

📦 Condition

  

• Brand new Dunbier Marine Products trailer component

• Supplied as one high-tensile bolt only

• Supplied in original or equivalent packaging

## Details

- **Price:** 11.0 AUD
- **Vendor:** Dunbier
- **Tags:** Dunbier Boat Trailers | Marine Trailer Parts & Accessories

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 11.00 AUD | In stock |

## Images

- 8945 Dunbier High-Tensile Bolt 5/8 x 9" Black | Marine Trailer Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/8945-dunbier-high-tensile-bolt-5-8-x-9-black)
> Updated: 2026-08-05