Railroad Track Bolt with Nut and Lock Washer

Railroad track bolt with a nut and lock washer form a heavy-duty, three-piece fastening system explicitly engineered under AREMA and ASTM guidelines to secure rail joints (fishplates) against extreme vibrations and lateral track forces. 

Kunshan Signum Machinery Technology Co., Ltd. Specializes in offering rail track bolts for railway fastening according to our customer's specific requirements. 

Specifications of Railroad Track Bolt

• Button Head Oval Neck (BHON): The bolt features a domed head with an elongated oval neck underneath. This oval profile drops into matching elliptical holes punched into the rail joint bars, completely locking the bolt body in place so you can torque the nut from the opposite side without needing a second wrench. 

• High-Tension Spring Washers: These setups do not use standard consumer flat washers. They rely on heavy-duty, split-ring AREMA-spec spring washers designed to exert massive continuous mechanical tension, preventing the nut from backing out under heavy axle loads. 

• Industrial Thread Material: Track bolts are usually forged out of heat-treated carbon steel (Grade 2) to achieve the mandatory tension threshold of 25,000 to 30,000 pounds of tension.

The railroad track bolt with nut and lock washer assembly is the standard mechanical fastening unit used to join rails together via joint bars (fishplates) or to secure critical track assets.

System Mechanics and Assembly Order

• The Role of the Lock Washer: Standard track assemblies utilize split-lock or high-tension AREMA spring washers. The washer maintains continuous tension against the nut, absorbing severe impact and preventing lateral displacement or thread-backing. 

• Correct Installation Stack: To establish an optimal mechanical lock, components must follow a specific sequence. The bolt passes through the joint bar, the lock washer is placed onto the threaded end first, and the heavy nut is torqued directly against the lock washer. 

• Alternating Directions: Per industry standards, track bolts are installed in alternating directions (one head inside the track, the next head outside the track) along the joint bar to protect the connection if a train wheel derails and shears off one side of the hardware. 

The railroad track bolt, nut, and lock washer assembly is a highly engineered, three-part fastening system. It serves as the primary mechanical joint used to clamp [rail joint bars (fishplates)] together or secure structural rail components at turnouts and frogs.Each part of the assembly performs a distinct mechanical job to ensure the track joint remains locked and structurally sound.