ISHB H-Beams — Wide Flange Heavy Sections

What is an ISHB H-Beam?

An ISHB (Indian Standard Heavy Beam) is a hot-rolled structural steel section with a cross-section shaped like the letter H. Unlike the I-shaped ISMB profile where the flange width is roughly half the depth, the ISHB profile has a flange width that is much closer to the section depth — typically 80–95% of the depth. This wider flange gives ISHB sections their characteristic "boxy" appearance and dramatically different structural behaviour from regular I-beams.

The wider flange increases the moment of inertia and radius of gyration about the minor (Y-Y) axis, which is the axis along which steel columns typically buckle when loaded in compression. The ISHB series is specifically designed for use as columns and compression members, where buckling about the weak axis governs design. ISMB beams, by contrast, are designed primarily for bending, where minor-axis properties matter less.

Quick rule of thumb: Use ISMB I-beams when the section is loaded in bending only (joists, lintels, simply supported beams). Use ISHB H-beams when the section carries axial load with possible bending (columns, posts, props, members in trusses subject to compression).

ISHB profiles per IS 808 : 1989

The Indian Standard specifies ISHB sections in 17 standard sizes, ranging from ISHB 150 to ISHB 450. Each nominal size is available in two or three weight variants — a light version with thinner web and a heavy version with thicker web for higher load capacity. The designations are written as ISHB 200 @ 37.3 kg/m (light) or ISHB 200 @ 40.0 kg/m (heavy), where the suffix denotes weight per metre.

// Indian Standard Heavy Beams (ISHB) — IS 808 : 1989

Designation	Depth (mm)	Flange (mm)	Web tw (mm)	Flange tf (mm)	Wt (kg/m)	Area (mm²)
ISHB 150	150	150	8.4	9.0	27.1	3450	View →
ISHB 150 H	150	150	11.8	9.0	30.6	3893	View →
ISHB 200	200	200	7.8	9.0	37.3	4754	View →
ISHB 200 H	200	200	9.0	9.0	40.0	5094	View →
ISHB 225	225	225	8.6	10.8	43.1	5494	View →
ISHB 225 H	225	225	10.5	10.8	46.8	5964	View →
ISHB 250	250	250	8.8	9.7	46.6	5942	View →
ISHB 250 H	250	250	10.5	9.7	50.4	6422	View →
ISHB 300	300	250	7.6	10.6	54.7	6971	View →
ISHB 300 H	300	250	9.4	10.6	58.8	7485	View →
ISHB 350	350	250	8.3	11.6	61.6	7846	View →
ISHB 350 H	350	250	10.1	11.6	67.4	8591	View →
ISHB 400	400	250	9.1	12.7	72.4	9227	View →
ISHB 400 H	400	250	10.6	12.7	77.4	9866	View →
ISHB 450	450	250	9.8	13.7	82.2	10466	View →
ISHB 450 H	450	250	11.3	13.7	87.2	11106	View →
ISHB 450 SH	450	250	13.5	13.7	92.5	11789	View →

Suffix: H = heavy, SH = super heavy. All sections rolled per IS 808 : 1989. Areas calculated from cross-section geometry; actual mass tolerance per IS 1852.

How H-beams differ from I-beams

The fundamental difference between ISMB I-beams and ISHB H-beams lies in their proportions and intended application. Both are wide-flange structural shapes, but the ratio of flange width to depth is dramatically different:

Property	ISMB (I-beam)	ISHB (H-beam)
Flange width / depth ratio	~0.50 (flange = half depth)	~0.85 to 1.00 (flange ≈ depth)
Primary loading mode	Bending (beams, joists)	Axial compression + bending (columns)
Strong-axis (Ix) inertia	High	Moderate
Weak-axis (Iy) inertia	Low	High (approaches Ix)
Buckling resistance about Y-Y	Poor	Excellent
Web thickness	Thin (4–12 mm)	Thick (7.6–13.5 mm)
Best application	Joists, purlins, simply supported beams, lintels	Columns, struts, props, compression chord of trusses
Weight efficiency	Lighter for given bending capacity	Lighter for given column capacity

The buckling story

When a steel column carries axial load, it can fail by buckling — bending sideways under compression like a soda can crushing. The lower the column's radius of gyration about its weakest axis, the more prone it is to buckling. For an I-beam, the weak axis (Y-Y) has a radius of gyration of perhaps 1/4 to 1/3 of the strong axis. For an H-beam, the two values are much closer — sometimes within 30%. This is what makes H-beams the natural choice for columns where buckling about either axis must be resisted.

International equivalents

ISHB sections do not have direct one-to-one equivalents in international standards because every standards body uses slightly different proportions. However, the following table shows the closest functional equivalents based on depth and weight:

ISHB (India)	HE-A (Europe)	HE-B (Europe)	UC (UK / EN)	W-shape (USA)
ISHB 150 @ 27.1	HE 140 A	HE 140 B	152×152×23 UC	W6×15
ISHB 200 @ 37.3	HE 200 A	HE 180 B	203×203×46 UC	W8×31
ISHB 250 @ 46.6	HE 240 A	HE 220 B	254×254×73 UC	W10×49
ISHB 300 @ 54.7	HE 280 A	HE 260 B	305×305×97 UC	W12×65
ISHB 350 @ 61.6	HE 320 A	HE 300 B	356×368×129 UC	W14×82
ISHB 400 @ 72.4	HE 360 A	HE 340 B	356×406×235 UC	W16×100
ISHB 450 @ 82.2	HE 400 A	HE 400 B	356×406×287 UC	W18×119

Equivalence is approximate, based on closest matching depth + weight combination. Always verify exact properties from the actual standard before substituting in design calculations.

Material grades

ISHB sections are produced in structural steel grades specified by IS 2062 : 2011 — Hot rolled medium and high tensile structural steel. The most common grades for H-beams are:

Grade	Yield strength (MPa, min)	Tensile strength (MPa, min)	Elongation (% min)	Typical use
E 250 (Fe 410W)	250	410	23	General construction, low-rise buildings
E 350	350	490	22	Multi-storey buildings, industrial structures
E 410	410	540	20	Heavy-duty columns, high-rise construction
E 450	450	570	20	Bridges, offshore structures
E 550	550	650	18	High-strength applications, weight-critical structures

Higher grades allow lighter sections to carry the same load — important for tall buildings where reducing self-weight on lower-floor columns has cascading benefits. However, higher grades come at a price premium and may have more restrictive welding procedures. For most building applications in India, E 250 remains the default choice unless engineering analysis shows that a higher grade reduces overall steel tonnage by more than the cost premium.

Typical applications

Multi-storey building columns — the dominant application. ISHB columns carry the gravity loads from all floors above and transfer them to the foundation.
Industrial structure columns — factory and warehouse main columns supporting roof trusses and crane gantries.
Crane gantry columns — heavy-duty columns supporting overhead travelling cranes in steel mills and fabrication shops.
Power transmission tower legs — for extra-high voltage (EHV) towers above 400 kV where standard angle sections become impractical.
Marine structures and jetties — main supporting columns for piers and dock structures, often in galvanised or weathering steel grades.
Bridge piers and bents — vertical supporting members of steel bridges and overpasses.
Compression members in trusses — top chords of long-span steel trusses where local buckling resistance is critical.
Heavy-duty struts and props — temporary works in construction, including soldier piles and braced excavations.

Ordering & specification

When ordering ISHB sections from a rolling mill, the standard specification format is:

Example: "ISHB 250 @ 46.6 kg/m, Grade E 250 to IS 2062, length 12 metres, mill certificate as per IS 1852, BIS standard tolerance class A."

The key elements of an ISHB order are:

Designation — section size (e.g., ISHB 250) and weight variant (light, H, or SH where applicable)
Grade — material grade per IS 2062 (E 250, E 350, E 410, etc.)
Length — most Indian mills supply standard 10, 11, 12, or 13 metre random lengths; cut-to-length is available at slight premium
Tolerance class — Class A (tighter, structural) or Class B (looser) per IS 1852
Surface condition — black (mill finish), shot blast cleaned, or pre-primed
Mill test certificate — TC1, TC2, or TC3 traceability per IS 1387

Frequently asked questions

Why does ISHB use the suffix H or SH?

The suffix denotes the web thickness variant. The base ISHB section has the lightest web, ISHB 200 has a 7.8 mm web. The "H" (heavy) variant has a thicker web (9.0 mm for ISHB 200 H), which increases shear capacity and overall section weight. The "SH" (super heavy) variant exists only for ISHB 450 and has the thickest web at 13.5 mm. The flanges remain identical across all variants of a given depth — only the web changes.

Can ISHB sections be used as beams?

Yes — and they often are. While ISHB is optimised for compression, the wider flange also provides good bending resistance about both axes. ISHBs are commonly used as floor beams in heavy industrial buildings, transfer girders, and crane runway beams. The trade-off is that for pure bending applications, an ISMB or ISWB section of the same depth weighs less and costs less per unit of bending capacity.

What is the difference between ISHB and ISWB?

ISWB stands for Indian Standard Wide flange Beam. Confusingly, both ISHB and ISWB have wider flanges than ISMB, but they are designed differently. ISWB sections have flange width slightly less than depth and are optimised for bending with higher minor-axis stiffness than ISMB. ISHB sections have flange width approximately equal to depth and are designed for combined axial + bending loads as columns. In practice: ISWB for heavy beams, ISHB for columns.

Are ISHB sections produced in India today?

Yes, all major Indian steel producers — SAIL, Tata Steel, JSW Steel, Jindal Steel & Power, and many secondary producers — roll the full ISHB range. The most popular sizes (ISHB 200, 250, 300) are widely available from stockists across India. Larger sizes (ISHB 400, 450) may need to be ordered directly from the mill for project quantities.

How does ISHB pricing compare to ISMB?

On a per-tonne basis, ISHB and ISMB are typically priced very close (within 5%), but per metre, ISHB sections are heavier and therefore cost more. The cost-effectiveness comparison depends on the engineering application: for columns carrying significant load, ISHB is almost always more economical than ISMB despite the higher per-metre cost, because the column can be lighter overall.

What rolling mill equipment is needed to produce ISHB sections?

ISHB sections require a universal mill with both horizontal and vertical rolls — the vertical rolls form the flange edges while the horizontal rolls form the inside of the flanges and the web. Universal mills are substantially more complex and expensive than simple two-high or three-high mills used for ISMB. They are typically only found in heavy section mills with capacities of 300,000 tonnes per year or more. Learn more about hot rolling mill configurations →

Related references

ISMB I-Beams (medium weight beams) — the standard I-beam profile for general bending applications
ISMC Channels — C-shaped sections for purlins and lateral framing
ISA Angles — L-shaped sections for bracing and trusses
Rolling Mills: Principles, Components, Processes, and Products — comprehensive technical reference
Hot Rolling Mills Guide — universal mills, section mills, layouts

Standards and references

IS 808 : 1989 — Dimensions for hot rolled steel beam, column, channel and angle sections (ISHB profile dimensions and tolerances)
IS 2062 : 2011 — Hot rolled medium and high tensile structural steel (material grades E 250 through E 650)
IS 1852 : 1985 — Rolling and cutting tolerances for hot rolled steel products
IS 800 : 2007 — General construction in steel — Code of practice (design code)
IS 1387 : 1993 — General requirements for the supply of metallurgical materials