What is the length of a fish bolt?

A rail fish plate is a steel joint reinforcement element that stabilizes rail ends against vertical deflection and lateral displacement under repeated service loads. It is essential for maintaining joint integrity in traditional track systems. GNEE RAIL supplies fish plates suitable for GB rails, UIC rails, DIN536 and QU crane rails, JIS standards, AS1085 rail sections, BS11 profiles, and AREMA/ASCE systems, along with surface treatment options.

Components of a rail joint

A standard rail joint connects two rail ends to ensure structural continuity, allowing for thermal expansion and contraction. Its primary components include two steel fishplates (splice bars) bolted to the rail web, fish bolts with nuts, and spring washers to maintain tension and absorb shock.

Key components include:

• Fishplates (Joint Bars): Metal plates, usually two, placed on either side of the rail web. They are engineered to fit the bevel of the rail head and bottom for a tight connection.

• Fish Bolts (Rail Bolts): High-strength bolts that pass through oval holes in both the fishplates and the rail web to secure the connection.

• Spring Washers: Used with the bolts to maintain constant tension and prevent the nuts from loosening due to vibration.

• Rail Holes: Oval-shaped holes in the rail web that accommodate the bolts and allow for thermal expansion/contraction.

• Insulation Components (in Insulated Joints): Specifically in glued insulated joints, these include insulation boards, plates, and glue to prevent electrical conductivity between rails.

What is the length of a fish bolt?

Fish bolts, used to secure rail joints, typically range in length from 45 mm to 145 mm (approx. 1.75 to 5.7 inches) for standard applications, though they can be found in lengths up to 300 mm or more depending on specific rail requirements. They commonly have diameters of 16 mm to 24 mm.

• Common Lengths: 45mm-145mm (Metric/General)

• Imperial Lengths: Frequently 4-1/2" or longer for specific joint bars.

• Diameter: Generally 16mm-24mm (M12-M24).

• Head/Neck Types: Button head, oval neck, or diamond neck.

Lengths are selected based on the thickness of the fish plates and the rail profile.

Why use a rail fish bolt?

Rail fish bolts are critical, high-strength fasteners used to secure fish plates (joint bars) to the ends of rails, ensuring structural integrity, maintaining track gauge, and preventing rail separation. They provide necessary rigidity to rail joints, withstand intense dynamic loads from passing trains, and allow for safe, smooth, and continuous railway operation.

• Structural Integrity and Safety: Fish bolts fasten fish plates to the sides of rail ends, preventing vertical or horizontal movement at the joint, which is essential to avoid derailments.

• High Strength and Durability: Made of materials like high-strength steel (often 8.8 or 10.9 grade), these bolts are designed to handle heavy, repetitive, and fluctuating loads, particularly in high-speed or heavy-haul railways.

• Anti-Loosening Performance: Due to the high vibration and stress at rail joints, fish bolts are designed to maintain high pretension, keeping the joint tight and stable.

• Ensuring Track Continuity: They ensure the smooth transition of wheels from one rail to the next, reducing impact forces at the joint.

• Versatility in Application: They are used in various railway settings, including standard track joints, railway switches (turnouts), and industrial tracks.

• Components of Fastening Systems: Usually, 4-6 sets of fish bolts are used per joint, accompanied by spring washers or nuts to ensure a secure, tightened connection.

Rail fish bolts are essential for preventing the misalignment or separation of rail tracks, thereby maintaining the stability of the entire rail infrastructure.

Founded in 2008, GNEE RAIL is a leading global manufacturer and supplier of railway components, specializing in high-quality rail fish plates (joint bars/splice bars) with strong production capacity and global service capabilities.

Our rail fish plate portfolio is comprehensive and compliant with international standards including UIC, AREMA, BS, DIN, and GB, covering light rail (8kg-30kg), heavy rail (38kg-75kg), and crane rail (QU70-QU120) systems. We offer diverse types such as insulated joint bars, bulged fish plates, and compromise rail joints,with precise specifications (4-hole/6-hole, 24-inch/36-inch), ensuring excellent mechanical performance.We uphold strict quality control supported by ISO 9001:2015 certification, an in-house inspection center, and third-party audits by SGS and BV. Our one-stop service includes customization, production, packaging, and after-sales support, tailored to clients' project needs.

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