IS 12778:2004 is the Indian Standard (BIS) for hot rolled parallel flange steel sections for beams, columns and bearing piles – dimensions and section properties. This standard specifies the dimensions, mass, and sectional properties for hot-rolled parallel flange steel beams (NPB, WPB) and bearing pile (PBP) sections. It serves as the primary reference for engineers and fabricators to select and use these modern, efficient structural members in construction.
Hot Rolled Parallel Flange Steel Sections for Beams, Columns and Bearing Piles – Dimensions and Section Properties
Hot-rolled parallel-flange beams, columns and bearing piles. Dimensions, properties, tolerances.
| Reference | Value | Clause |
|---|---|---|
| Section types covered | wide-flange (W), heavy beam (H), columns | Cl. 3 |
| ISWB section depths | 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 550, 600 mm | Cl. 4 (Table 1) |
| ISWB 150 — mass per metre | 17.0 kg/m | Cl. 4 (Table 1) |
| ISWB 200 — mass per metre | 28.8 kg/m | Cl. 4 (Table 1) |
| ISWB 250 — mass per metre | 40.9 kg/m | Cl. 4 (Table 1) |
| ISWB 300 — mass per metre | 50.0 kg/m | Cl. 4 (Table 1) |
| ISWB 400 — mass per metre | 75.6 kg/m | Cl. 4 (Table 1) |
| ISWB 500 — mass per metre | 102.7 kg/m | Cl. 4 (Table 1) |
| ISWB 600 — mass per metre | 137.0 kg/m | Cl. 4 (Table 1) |
| ISHB section depths | 150, 200, 225, 250, 300, 350, 400, 450 mm | Cl. 5 (Table 2) |
| ISHB 200 — mass per metre | 37.3 kg/m (light) to 47.0 kg/m (heavy) | Cl. 5 (Table 2) |
| ISHB 300 — mass per metre | 58.8 to 63.0 kg/m | Cl. 5 (Table 2) |
| ISHB 400 — mass per metre | 77.4 to 82.2 kg/m | Cl. 5 (Table 2) |
| ISHB 450 — mass per metre | 87.2 to 92.5 kg/m | Cl. 5 (Table 2) |
| Tolerance on depth | ± 2 mm | Cl. 6 (Table 4) |
| Tolerance on flange width | ± 2 mm | Cl. 6 (Table 4) |
| Tolerance on web thickness | ± 0.5 mm | Cl. 6 (Table 4) |
| Tolerance on mass per metre | ± 4 % | Cl. 6 (Table 4) |
| Length tolerance — standard | ± 100 mm (for length ≤ 12 m) | Cl. 6.4 |
| Material | as per IS 2062 (Fe-410W typical) | Cl. 7 |
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
IS 12778:2004 specifies the dimensions and section properties of hot-rolled parallel-flange steel sections for beams, columns and bearing piles — the modern wide-flange (parallel-flange) I/H sections (UB/UC/bearing-pile type) that have largely replaced the older tapered-flange ISMB/ISMC sections for efficient structural steelwork. Design is to IS 800; this provides the section geometry and properties.
It sits in the steel-section stack:
Parallel-flange sections are the modern structural-steel workhorse for good reasons, and IS 12778 gives the geometry/properties IS 800 design needs:
The engineering point: parallel-flange sections are preferred for efficiency and connection simplicity, and the design relies on the tabulated section properties for the specified designation — substituting a different section (older tapered-flange or a different size) silently changes capacity, stiffness and connection geometry. Use the standard sections and their properties, with the IS 12779 rolling tolerances in mind for critical members.
Scenario: a steel beam/column (or bearing pile) in a building/structure designed to IS 800.
Step 1 — design demand → section: IS 800 checks (strength/buckling/deflection) give the required section properties → pick the standard IS 12778 parallel-flange designation that provides them.
Step 2 — use the tabulated properties: take area/I/Z/r for that exact designation from IS 12778 for the member checks and connections.
Step 3 — connection advantage: exploit the parallel flanges for simpler bolted/welded connections (no taper packing).
Step 4 — tolerances: allow for IS 12779 rolling/cutting tolerances on critical members; verify delivered section/designation.
Step 5 — material/quality: the steel quality is IS 2062; this spec is geometry/properties.
Standard designation + its tabulated properties + correct tolerances = the member the design intended; a substituted section changes capacity and connections invisibly.
1. Substituting a different section for the designed one. Section properties (capacity/stiffness) and connection geometry change — verify the delivered designation.
2. Confusing parallel-flange with old tapered ISMB/ISMC. Different geometry/properties/connection detailing — use the correct table.
3. Treating it as a quality spec. It is dimensions/properties; steel quality is IS 2062.
4. Ignoring rolling tolerances on critical members. Allow IS 12779 tolerances where section is critical.
5. Designing non-standard sizes. Off-standard sections may be unavailable/uneconomical — design to standard designations.
IS 12778 is current (2004) and provides the geometry/properties of the modern parallel-flange sections that have largely displaced the older tapered ISMB/ISMC for efficient structural steel — better material efficiency and, importantly, cleaner connections (no flange taper to pack or cope). The practitioner essentials are simple: design to IS 800 using the tabulated section properties for the specified designation, exploit the parallel-flange connection advantage, allow for IS 12779 rolling tolerances on critical members, and verify the delivered designation — substituting a different (or old tapered) section silently changes capacity, stiffness and connection geometry. It is a dimensions/properties standard (quality is IS 2062); its value is ensuring the member built is the member designed, with the efficiency and connection benefits parallel-flange sections were adopted for.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Nominal Depth (h) | 200 mm | 200 mm | EN 10365:2017 (HEB 200) |
| Flange Width (b) | 200 mm | 200 mm | EN 10365:2017 (HEB 200) |
| Web Thickness (tw) | 9.0 mm | 9.0 mm | EN 10365:2017 (HEB 200) |
| Flange Thickness (tf) | 15.0 mm | 15.0 mm | EN 10365:2017 (HEB 200) |
| Root Radius (r1/r) | 18 mm | 18 mm | EN 10365:2017 (HEB 200) |
| Mass per meter (kg/m) | 61.3 kg/m | 61.3 kg/m | EN 10365:2017 (HEB 200) |
| Moment of Inertia Ix-x (cm^4) | 6066 cm^4 | 6060 cm^4 | EN 10365:2017 (HEB 200) |
| Flange Width (b) for 400 mm Nominal Depth I-section | 200 mm (ISWB 400) | 180 mm (IPE 400) | EN 10365:2017 |