What are the main grades of rails specified in IS 16733?

The main grades are R 260, 880, 1080 Cr, and Head Hardened grades like R 350 HT. (Clause 4)

What are the standard lengths for rails?

Standard lengths are 13 m and 26 m. They can also be supplied as long welded rails (LWR) up to 260 m. (Clause 11.6)

What is the minimum hardness for a Grade R 260 rail?

The hardness must be between 260 and 300 BHN. (Table 3)

What is the difference between Class 'A' and Class 'B' rails?

Class 'A' rails have stricter controls on hydrogen content (<1.6 ppm) and ultrasonic testing acceptance criteria, making them suitable for more demanding applications. (Clause 5.4.1 & 13.5)

IS 16733

: 2018

Hot Rolled Steel Rails for Railway Tracks - Specification

CurrentEssentialSpecificationBIMTransportation · Railway Engineering

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This standard specifies the requirements for hot-rolled steel rails used in railway tracks. It covers manufacturing, chemical composition, mechanical properties, geometric dimensions, testing procedures, and classification for various grades of rails.

Specifies requirements for hot rolled steel rails of various grades used in railway tracks, representing modern standards.

Quick Reference Values

Maximum Hydrogen Content (Class A rails)1.6 ppm

Minimum Tensile Strength (Grade R 260)880 MPa

Minimum Brinell Hardness (Grade R 260)260 BHN

Maximum Sulphur Content0.020 %

Maximum Phosphorus Content0.020 %

Standard Rail Length13 m or 26 m

Minimum Elongation (Grade R 260)10 %

Practical Notes

This single standard harmonizes and replaces six previous IS codes for different types of rails, simplifying procurement and specification.

Pay close attention to the rail class ('A' or 'B') as Class 'A' has much stricter controls on hydrogen content and internal defects, intended for high-speed or heavy-haul routes.

The grade designation (e.g., R 260) directly corresponds to the minimum specified Brinell hardness (BHN), making identification easier.