Hex Head M18*57MM Track Bolts and Nuts Compatible with the Track GP./DH220 EX200 PC200 EC140 etc.
Product Specifications
Overview
An M18 x 1.5 x 57mm Track Bolt is a specialized fastener designed to securely fasten railway tracks to the underlying sleepers (ties). They are known for their heavy-duty construction, specific head shape, and the use of a matching Track Nut, often with a integrated flange or a washer face.
1. Track Bolt Specification Breakdown
Let's decode "M18 x 1.5 x 57MM":
M18: The "M" stands for Metric. The "18" is the nominal major diameter of the bolt thread, which is 18 mm.
1.5: This is the pitch of the thread, meaning the distance between adjacent threads is 1.5 mm. This is a fine thread, which provides better vibration resistance compared to a standard coarse thread (which would be M18x2.5).
57MM: This is the length of the bolt. For track bolts, this is typically measured from under the head to the end of the shank.
Key Characteristics of the Bolt:
Head: Usually has a Counter-sunk (or Oval) Head or a Square Head.
Counter-sunk Head: This is the most common type. It sits flush with the surface of the rail base when installed, preventing any obstruction to equipment or workers moving along the track.
Square Head: Designed to be gripped by a wrench to prevent the bolt from spinning during nut installation. It fits into a square recess in the rail clip or tie plate.
Shank: The unthreaded section under the head is often a larger diameter than the threaded portion, providing extra strength where the shear forces are highest.
Material & Finish: Typically made from medium carbon steel (e.g., Grade 8.8, C45) or high-strength steel (e.g., Grade 10.9). The finish is often Hot-Dip Galvanized (HDG) or Geomet to provide excellent corrosion resistance for long-term outdoor exposure.
Dimensional Example (Typical):
| Feature | Typical Dimension |
|---|---|
| Thread Diameter | 18 mm |
| Thread Pitch | 1.5 mm |
| Shank Length | ~57 mm (Total length can vary slightly) |
| Head Style | Oval / Counter-sunk or Square |
| Head Width (Square) | ~27 mm |
| Shank Diameter | ~20 mm |
2. Track Nut Specification
The nut is specifically designed to work with the track bolt.
Thread: M18 x 1.5 to match the bolt.
Style: Almost always a Flanged Nut or Heavy Hex Nut.
Flanged Nut: Has a wide, integrated washer-like base. This distributes the clamping force over a larger area, reduces embedding into the sleeper, and speeds up installation by eliminating a separate washer.
Material & Finish: Matches the bolt (e.g., Grade 8, HDG) to ensure consistent strength and corrosion resistance.
Driving Feature: Typically a Hex (e.g., 27 mm across flats).
3. Common Applications
Railway Tracks: The primary use is to secure flat-bottom rails to concrete, steel, or wooden sleepers.
Crane Rails: Used in industrial settings for securing heavy-duty crane runways.
Mining Tracks: In mine shafts and tunnels where robust and reliable fastening is critical.
Other Heavy-Guide Rail Systems: Any application requiring a secure, flush-mounting bolt for a rail.
4. Installation and Assembly
The bolt is inserted through a hole in the base of the rail and the sleeper (or a specialized shoulder in the rail clip).
If it's a square head bolt, the head is locked into place in a square pocket to prevent rotation.
The track nut is then torqued onto the bolt from the other side.
A spring washer or split lock washer is almost always used between the nut and the sleeper to maintain tension and prevent loosening from vibrations.
