Comparison of High-strength Fishtail Bolts and Ordinary Bolts

Fishtail bolt is a kind of rail fastener used with rail joints. There are many kinds of fishtail bolts in the railroad material market, and for some new buyers, they don't know how to choose fishtail bolts. YONGYANG Rail, as a professional railroad fastener manufacturer, will help you better understand fishtail bolts and choose fishtail bolts easily in this article.

The material of fishtail bolts is low carbon alloy steel or medium carbon steel, quenched and tempered, called high strength fishtail bolts. The rest are called ordinary fishtail bolts. High-strength fishtail bolts are made of high-strength steel or require a large preload. High-strength insulated bolts are used to fix rails. It is a kind of rail fasteners, such as rail clamps, road spikes, threaded road spikes, spacers, rail joint rods, etc. High-strength fishtail bolts are mostly used for bridge or rail connection.

High strength insulated bolts and fishtail bolts are two common types of rail bolts. Let's talk about the difference between them.

Fish Bolts

High Strength and Common Bolts

High-strength fishtail bolts are designed to withstand greater loads than ordinary bolts of the same size. Ordinary fishtail bolts are made of Q235 (A3).

From the material point of view, high-strength fishtail bolts are made of high-strength materials. Bolts, nuts and washers are made of high-strength steel, such as 45 steel, 40 boron steel, 20 manganese titanium boron steel, etc. Ordinary bolts are usually made of Q235 steel.

In terms of strength grades, high-strength fishtail bolts are widely used. Two common strength grades include 8.8s and 10.9s, with 10.9 being the most common. The strength of common fishtail bolts is much lower at 4.8, 6.8, and 6.8 grades. 

According to the force characteristics, high-strength fishtail bolts apply preload and transmit external force through friction. Ordinary fishtail bolts rely on the shear force of the bolt rod and the pressure of the hole wall to transmit the shear force. The preload force generated when tightening the nut is so small that its effect is negligible.

In terms of the use of fishtail bolts, ordinary fishtail bolts can be reused, but high-strength fishtail bolts cannot be reused. High-strength bolts are usually used for permanent connections. Ordinary fishtail bolts have poor shear resistance and can be used for secondary structures.

Rail Spike

In summary, high-strength fishtail bolt connection has the advantages of simple construction, good mechanical properties, demountable, fatigue resistance, and does not loosen under the action of dynamic load, etc. It is a promising connection method. If you are looking for a reliable manufacturer of railroad fasteners, please contact us to get cooperation, YONGYANG has decades of experience and we are confident to provide you with unique solutions.