ISMB weight chart

14 sizes · 8.95 to 121.00 kg/m

Weight per metre, dimensions and section properties of every ISMB (medium flange beam) size in IS 808:2021, with the IS 808:1989 and 1964 handbook weights that older charts quote. Sections are listed from lightest to heaviest; Indian Standard (IS 808).

Download PDF Weight of 6 m / 12 m lengths FAQ

Section	h (mm)	b (mm)	tw (mm)	tf (mm)	kg/m	lb/ft	A (cm²)	Ix (cm⁴)	Iy (cm⁴)	Zx (cm³)	1989 kg/m	1964 kg/m
ISMB 100	100	50	4.7	7	8.95	6.01	11.40	182	12.50	36.40	8.90	11.5
ISMB 125	125	70	5	8	13.35	8.97	17.00	445	38.40	71.30	13.30	13.0
ISMB 150	150	75	5	8	14.96	10.05	19.00	718	46.70	95.70	15.00	14.9
ISMB 175	175	85	5.8	9	19.50	13.10	24.80	1,260	76.60	144	19.60	19.3
ISMB 200	200	100	5.7	10	24.17	16.24	30.80	2,110	136	211	24.20	25.4
ISMB 225	225	110	6.5	11.8	31.15	20.93	39.70	3,440	218	306	31.10	31.2
ISMB 250	250	125	6.9	12.5	37.30	25.06	47.50	5,130	334	410	37.30	37.3
ISMB 300	300	140	7.7	13.1	46.02	30.92	58.60	8,990	486	599	46.00	44.2
ISMB 350	350	140	8.1	14.2	52.33	35.16	66.70	13,600	537	779	52.40	52.4
ISMB 400	400	140	8.9	16	61.55	41.36	78.40	20,400	622	1,020	61.50	61.6
ISMB 450	450	150	9.4	17.4	72.38	48.64	92.20	30,400	834	1,350	72.40	72.4
ISMB 500	500	180	10.2	17.2	86.88	58.38	110.00	45,200	1,360	1,800	86.90	86.9
ISMB 550	550	190	11.2	19.3	103.64	69.64	132.00	64,900	1,830	2,360	104.00	103.7
ISMB 600	600	210	12	20.3	121.00	81.31	154.00	90,200	2,570	3,000	123.00	122.6

Source: IS 808:2021; earlier weights from IS 808:1989 and SP 6(1):1964, as published by Public.Resource.Org. Nominal values for estimating; verify with the producer. steelweight-calculator.com

Weight across the series

Weight per metre of every size, lightest to heaviest. ISMB 200, the size looked up most often, is highlighted.

How to read this chart

ISMB 200, drawn to scale (mm)

h: overall depth in mm
b: flange width in mm
tw: web thickness in mm
tf: flange thickness in mm (mean value for taper flanges)
kg/m, lb/ft: nominal weight per unit length
A: cross-sectional area in cm²; weight = 0.785 × A kg/m
Ix: second moment of area about the strong axis in cm⁴, which governs bending stiffness and deflection
Iy: second moment of area about the weak axis in cm⁴, which matters for buckling and columns
Zx: elastic section modulus in cm³; bending moment capacity is roughly Zx × allowable stress

Beams of this shape are used as floor and roof beams, lintels, crane girders and frame members, where bending about the strong axis governs.

Weight of standard lengths

Sections are usually supplied in 6 m and 12 m lengths. The weight of one piece is the weight per metre times the length; the last column converts a tonnage order into a number of 12 m bars.

Section	6 m length (kg)	12 m length (kg)	12 m lengths per tonne
ISMB 100	53.7	107.4	9.3
ISMB 125	80.1	160.2	6.2
ISMB 150	89.8	179.5	5.6
ISMB 175	117.0	234.0	4.3
ISMB 200	145.0	290.0	3.4
ISMB 225	186.9	373.8	2.7
ISMB 250	223.8	447.6	2.2
ISMB 300	276.1	552.2	1.8
ISMB 350	314.0	628.0	1.6
ISMB 400	369.3	738.6	1.4
ISMB 450	434.3	868.6	1.2
ISMB 500	521.3	1,042.6	1.0
ISMB 550	621.8	1,243.7	0.8
ISMB 600	726.0	1,452.0	0.7

How the weight is calculated

The weight of a steel section is its cross-sectional area times the density of steel, 7850 kg/m³. With the area in cm² this simplifies to:

weight (kg/m) = 0.785 × A (cm²)

Example: ISMB 200 has an area of 30.80 cm², so 0.785 × 30.80 = 24.18 kg/m. The standard gives 24.17 kg/m, and a 12 m length weighs about 290.0 kg.

Rolled sections are made to a nominal mass, and the actual mass can differ by a few percent within the tolerances of IS 1852. For purchasing, invoicing by weight or checking deliveries, use the producer's stated mass.

More on the method: steel weight formula · density of steel · steel weight calculator

Old and new weights: 1964, 1989 and 2021

Many ISMB weight charts in circulation still use the 1964 ISI Handbook SP 6(1). IS 808 was revised in 1989 (and again in 2021), and several sizes were rolled to different dimensions. These 6 sizes differ by more than 1 % from the current standard:

Section	1964 kg/m	1989 kg/m	2021 kg/m	1964 vs 2021	per 12 m
ISMB 100	11.5	8.90	8.95	+28.5 %	+30.6 kg
ISMB 125	13	13.30	13.35	-2.6 %	-4.2 kg
ISMB 175	19.3	19.60	19.50	-1.0 %	-2.4 kg
ISMB 200	25.4	24.20	24.17	+5.1 %	+14.8 kg
ISMB 300	44.2	46.00	46.02	-4.0 %	-21.8 kg
ISMB 600	122.6	123.00	121.00	+1.3 %	+19.2 kg

When a supplier quotes weights, ask which table they use, and check the mill test certificate for the dimensions actually rolled. For estimates and design, use the current standard.

Equivalent sections in other standards

The closest section in each other standard by depth and weight. These are starting points for substitution, not drop-in replacements: flange width, thickness and section properties differ, so check the design.

Section	kg/m	European (EN)	American (AISC / ASTM A6)
ISMB 100	8.95	IPE 100 (8.1 kg/m)	M4x6 (8.9 kg/m)
ISMB 125	13.35	IPE 140 (12.9 kg/m)	S5x10 (15.0 kg/m)
ISMB 150	14.96	IPE 160 (15.8 kg/m)	W6x9 (13.5 kg/m)
ISMB 175	19.50	IPE 180 (18.8 kg/m)	S6x12.5 (18.6 kg/m)
ISMB 200	24.17	IPE 200 (22.4 kg/m)	W8x15 (22.5 kg/m)
ISMB 225	31.15	IPE 240 (30.7 kg/m)	W8x21 (31.3 kg/m)
ISMB 250	37.30	IPE 270 (36.1 kg/m)	S10x25.4 (37.8 kg/m)
ISMB 300	46.02	IPE 300 (42.2 kg/m)	S12x31.8 (47.3 kg/m)
ISMB 350	52.33	IPE 360 (57.1 kg/m)	W14x34 (51.0 kg/m)
ISMB 400	61.55	IPE 400 (66.3 kg/m)	W16x40 (60.0 kg/m)
ISMB 450	72.38	IPE 450 (77.6 kg/m)	W18x50 (74.0 kg/m)
ISMB 500	86.88	IPE 500 (90.7 kg/m)	S20x66 (98.2 kg/m)
ISMB 550	103.64	IPE 550 (105.5 kg/m)	W21x68 (101.0 kg/m)
ISMB 600	121.00	IPE 600 (122.5 kg/m)	S24x80 (119.0 kg/m)

Full matching tables: steel section equivalents.

Choosing a size

For a beam, bending capacity grows with the elastic section modulus Zx, while cost grows with weight. Per kilogram of steel, the most efficient sizes in this chart are ISMB 600 (24.8 cm³ per kg/m), ISMB 550 (22.8 cm³ per kg/m), ISMB 500 (20.7 cm³ per kg/m). Deeper, lighter sections usually win in bending; wider flanges (or a heavier section of the same depth) help where lateral buckling, column loads or limited depth govern. Deflection depends on Ix.

Frequently asked questions

What is the weight of ISMB 200?

ISMB 200 weighs 24.17 kg/m (16.24 lb/ft). A 6 m length is about 145.0 kg and a 12 m length about 290.0 kg.

What are the lightest and heaviest sizes in this chart?

The lightest is ISMB 100 at 8.95 kg/m (6.01 lb/ft) and the heaviest is ISMB 600 at 121 kg/m (81.31 lb/ft). The chart lists 14 sizes.

How is the weight of an ISMB medium weight beam calculated?

Weight per metre is the cross-sectional area times the density of steel, 7850 kg/m³. With the area in cm², that is mass = 0.785 × A kg/m. For ISMB 200, A = 30.80 cm², so 0.785 × 30.80 = 24.18 kg/m. Multiply by the length in metres for the weight of a piece.

Why do different ISMB charts show different weights?

Older charts copy the 1964 ISI handbook SP 6(1). IS 808 was revised in 1989 and several sizes changed: ISMB 200 was 25.4 kg/m in 1964 and is 24.17 kg/m in IS 808:2021. 6 of the 14 sizes differ by more than 1 %. This chart uses IS 808:2021 and lists the older figures alongside.

Which ISMB gives the most bending strength per kilogram?

Measured by elastic section modulus per kg of weight, ISMB 600 is the most efficient in this chart (Zx = 3,000 cm³ for 121 kg/m). Deeper sections are generally more efficient in bending; check deflection, lateral buckling and available depth before choosing.

Is there a printable ISMB weight chart?

Yes. The PDF version of this chart (steelweight-calculator.com/charts/ismb-weight-chart.pdf) has the same table on A4 pages and can be printed or saved for site use.