Heavy rails can be divided into general rails and crane rails according to their uses. General rails refer to rails used for laying railway trunk lines, special lines, curves and tunnels, and crane rails are mainly used on the guide rails of cranes.
Crane rails include crane rails, railway rails and square steel. The top of the rail is convex, and the bottom is a flat plate with a certain width, which increases the contact surface with the base. Most of the cross-sections of the guide rails are I-shaped and have good bending strength. Crane rails are special cross-section rails used for crane trolleys and trolleys. Common specifications are QU70, QU80, QU100, QU120. The number after QU indicates the width of the rail head. The commonly used grade is U71Mn. Generally, only chemical composition and tensile strength are required to be tested.