Frog Bolts

Frog bolts are a type of specialized high-strength bolt used in railway systems, primarily on railway switches. The main function of these frog bolts is to connect and secure the various parts of the switch system. AGICO’s frog bolts are made from medium carbon or alloy steel and can be manufactured with either a square or round head. They are typically used together with AGICO’s security locknut, which is custom-made from nylon or metal materials and functions similarly to a hardlock nut. The head is usually larger than the diameter of the screw, and after being hammered into a pre-drilled hole, the head expands to form a larger bearing surface, thereby increasing the anchoring force. Frog bolts are one of the most crucial components of railway switches, as the switch area consists of two or more intersecting tracks where trains complete the track exchange. During the track exchange, the rails at the switch area endure greater vertical pressure and wheel torque than other parts. Therefore, the frog bolts used at the switch area need to be stronger and longer to ensure the safety of the train. Otherwise, it could lead to switch collisions or derailments.
AGICO manufactures frog bolts in various lengths and diameters, with the best-selling ones being the 1-3/8″ diameter frog bolts and the 1-1/8” diameter frog bolts, with shank diameters of 1-3/8 inches (approximately 34.93 mm) and 1-1/8 inches (approximately 28.575 mm), respectively. Common lengths include 50mm, 75mm, and 100mm, among others, which can be customized according to different needs. Frog bolts are suitable for various rail section sizes in railway switches. For example, M22 and M24 switch bolts are typically used for 43kg switches, while M24 and M27 frog bolts are usually used for 50kg switches. AGICO can also customize frog bolts according to the customer’s drawing requirements. This type of railway fastener is particularly popular with US and UK customers.