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IS 1173:1978 is the Indian Standard (BIS) for hot rolled and slit steel tee bars. This standard specifies the nominal dimensions, mass, and sectional properties (area, moments of inertia, radii of gyration) of hot-rolled and slit structural steel tee bars. It serves as a geometric and physical property catalog for structural engineers and detailers designing structural steelwork.
Hot rolled and slit steel tee bars
Overview
Status
Current
Usage level
Specialized
Domain
Structural Engineering — Structural Engineering and Structural Sections
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! Always verify the commercial availability of specific tee sections with local suppliers before specifying them, as rolling mills frequently only produce the most common sizes.
! When ready-rolled tee sections are unavailable, they are often substituted by slitting standard I-beams (ISMB) longitudinally.
! This code provides standard dimensions and properties, but rolling and cutting tolerances must be referred to IS 1852.
EN 10055:1995CEN (European Committee for Standardization), Europe
HighCurrent
Hot rolled steel equal flange tee bars with radiused root and toes — Dimensions and tolerances on shape and dimensions
Specifically covers dimensions and tolerances for hot-rolled equal flange tee bars, similar to the ISTB and ISLT series in IS 1173.
ASTM A6/A6M - 24ASTM International, USA
HighCurrent
Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
Defines general requirements, including dimensional and mass tolerances, for all structural shapes, including tee sections (WT, MT, ST).
AS/NZS 3679.1:2016Standards Australia / Standards New Zealand, Australia/New Zealand
HighCurrent
Structural steel - Part 1: Hot-rolled bars and sections
Comprehensive standard covering material, dimensions, and tolerances for hot-rolled sections, including tees cut from universal beams.
JIS G 3192:2014JSA (Japanese Standards Association), Japan
MediumCurrent
Dimensions, mass and permissible variations of hot rolled steel sections
Covers dimensions and tolerances for various hot-rolled sections, including T-sections cut from H-beams, similar to ISST series.
Key Differences
≠IS 1173 specifies unique section designations (e.g., ISTB, ISLT, ISST) and dimensional series that are not directly interchangeable with European (T), American (WT, MT, ST), or other international series.
≠IS 1173 explicitly defines 'slit tee bars' (ISST) cut from specific Indian Standard Medium Beams (ISMB), whereas ASTM defines cut tees (WT, ST) from their own W- and S-shape series.
≠The specific numerical values for dimensional and mass tolerances differ. For example, the mass tolerance in IS 1173 is ±2.5% for individual bars, while in EN 10055 it is ±4.0%.
≠IS 1173 references Indian material standard IS 2062 for chemical and mechanical properties, which has different grade designations (e.g., E250) and property limits compared to international counterparts like EN 10025-2 (S275) or ASTM A36.
Key Similarities
≈All standards cover tee sections manufactured by the hot-rolling process, either as a rolled shape or cut from a parent beam.
≈All standards act primarily as dimensional and tolerance specifications, referencing separate, broader material standards for chemical composition and mechanical properties.
≈All standards specify permissible deviations for key geometric parameters such as depth, width, thickness, straightness, and mass.
≈The fundamental technical requirements for marking, testing, and delivery conditions are conceptually similar, ensuring product traceability and quality control.
Parameter Comparison
Parameter
IS Value
International
Source
Referenced Material Standard (Typical)
IS 2062 - Hot Rolled Medium and High Tensile Structural Steel
EN 10025-2 - Hot rolled products of structural steels
EN 10055:1995
Yield Strength (Typical Grade)
≥ 250 MPa (for Grade E250A, t < 20mm)
≥ 275 MPa (for Grade S275JR, t ≤ 16mm)
EN 10025-2:2019
Tensile Strength (Typical Grade)
≥ 410 MPa (for Grade E250A)
410-560 MPa (for Grade S275JR, 3mm < t ≤ 16mm)
EN 10025-2:2019
Mass Tolerance (Individual Bar)
± 2.5%
± 4.0%
EN 10055:1995
Mass Tolerance (Batch/Lot)
± 2.0% (for a batch)
± 2.5% (for a lot ≥ 10 tonnes)
EN 10055:1995
Straightness Tolerance (Camber)
Shall not exceed 0.2% of the length
1/8 in. x (Total length in ft / 5) [approximates to 0.21% of length]
ASTM A6/A6M - 24
Depth Tolerance (h > 75 to 150 mm)
± 2.5 mm
± 2.0 mm (for h > 80 to 120 mm)
EN 10055:1995
⚠ Verify details from original standards before use
Key Values5
Quick Reference Values
ISNTIndian Standard Normal Tee Bars
ISHTIndian Standard Heavy Tee Bars
ISLTIndian Standard Light Tee Bars
ISJTIndian Standard Junior Tee Bars
ISSTIndian Standard Special Tee Bars
Tables & Referenced Sections
Key Tables
Table 1 - Dimensions and properties of Normal Tee Bars (ISNT)
Table 2 - Dimensions and properties of Heavy Tee Bars (ISHT)
Table 3 - Dimensions and properties of Special Tee Bars (ISST)
Table 4 - Dimensions and properties of Light Tee Bars (ISLT)