HSS Hollow Sections: CHS, SHS, RHS Sizes

Quick Reference

HSS (Hollow Structural Sections) come in 3 shapes: CHS (circular/round), SHS (square), RHS (rectangular). Standards: ASTM A500 (US), EN 10210/10219 (EU), ISO 657. Applications: columns, beams, architectural features, machinery frames. High strength-to-weight ratio, aesthetic appeal, can be galvanized for corrosion resistance. Use our steel weight calculator for weight estimation.

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Need a printable version? Download the HSS Hollow Sections Chart for CHS, SHS, RHS dimensions and weights.

Structural Hollow Sections (HSS)

What Are Hollow Sections?

Hollow Structural Sections (HSS) are steel profiles with a closed cross-section - round, square, or rectangular. The hollow core gives them a high strength-to-weight ratio: for a given weight of steel, an HSS column resists buckling far better than a solid bar or an open profile like an angle or channel.

HSS are produced by cold-forming steel strip or plate into shape and welding the seam (the most common method), or by hot-finishing seamless tube. The resulting section has uniform properties around its perimeter, which matters for columns and members loaded from multiple directions.

In practice, HSS are everywhere: building columns, truss members, handrail posts, pipe racks, equipment skids, trailer frames, and architectural exposed steelwork. Architects like them because they look clean; engineers like them because they work efficiently in compression and torsion.

Hollow structural section types: CHS, SHS, and RHS

HSS Types (Shapes)

The three standard shapes serve different structural purposes:

HSS hollow sections

Circular Hollow Sections (CHS) have the best structural efficiency for axial compression and torsion. No corners means no stress concentrations, and equal stiffness in all directions. CHS are the standard choice for truss members, offshore jacket legs, and columns with multi-directional loading. The downside is that connections are more complex - cutting and welding curved surfaces requires profile cutting machines and saddle-shaped preparation.

Square Hollow Sections (SHS) offer equal stiffness in both principal axes (like CHS) but with flat faces that make connections straightforward - you can bolt or weld flat plates directly. SHS are common in columns, posts, and frameworks where loads come from two directions. The corners are cold-worked during forming, which increases hardness locally but also makes them more susceptible to fatigue cracking if welded without care.

Rectangular Hollow Sections (RHS) have different stiffness in each direction - strong axis and weak axis, like an I-beam but closed. This makes them efficient for beams and members loaded primarily in one plane. RHS are standard for purlins, girts, crane runway supports, and any application where bending resistance in one direction governs the design.

Specifications

The key difference between US and European standards is the manufacturing route and how tolerances are handled.

Standard	Region	Manufacturing	Key Feature
ASTM A500	US	Cold-formed, welded or seamless	Most common US spec. Grades B and C. Allows 10% negative wall thickness tolerance.
ASTM A1085	US	Cold-formed, welded	Newer spec. Tighter tolerances, guaranteed minimum wall thickness (no 10% underrun). Single grade: 50 ksi yield.
EN 10210	Europe	Hot-finished	Better mechanical properties through corners (no cold-work residual stress). Standard grades: S235, S275, S355.
EN 10219	Europe	Cold-formed, welded	Equivalent to ASTM A500 in concept. Same EN 10025 grades. Corner properties reduced by cold-forming.

For structural design, the choice between hot-finished (EN 10210) and cold-formed (EN 10219 / ASTM A500) matters at the corners. Hot-finished HSS have more uniform properties because the final sizing happens at high temperature, relieving cold-work stresses. Cold-formed HSS have harder, stronger corners but with reduced ductility - relevant for welded connections and seismic design.

ASTM A1085 was created specifically to fix a long-standing problem with A500: the 10% negative wall thickness tolerance meant that a nominally 1/2” wall could legally be 0.450”. A1085 eliminates this, guaranteeing actual minimum wall thickness. For columns and exposed members where consistent properties matter, A1085 is worth specifying.

HSS Dimensions and Weights

CHS Round Hollow Section Sizes

Round/Circular Hollow Sections (CHS)

CHS Size	Weight (kg./m)	Diameter (mm)	Wall Thickness (mm)
21.3 x 3.2	1.4	21.3	3.2
26.9 x 3.2	1.9	26.9	3.2
33.7 x 2.6	2	33.7	2.6
33.7 x 3.2	2.4	33.7	3.2
33.7 x 4	2.9	33.7	4
42.4 x 2.6	2.6	42.4	2.6
42.4 x 3.2	3.1	42.4	3.2
42.4 x 4	3.8	42.4	4
48.3 x 3.2	3.6	48.3	3.2
48.3 x 4	4.4	48.3	4
48.3 x 5	5.3	48.3	5
60.3 x 3.2	4.5	60.3	3.2
60.3 x 4	5.6	60.3	4
60.3 x 5	6.8	60.3	5
76.1 x 3.2	5.8	76.1	3.2
76.1 x 4	7.1	76.1	4
76.1 x 5	8.8	76.1	5
88.9 x 3.2	6.8	88.9	3.2
88.9 x 4	8.4	88.9	4
88.9 x 5	10.3	88.9	5
114.3 x 3.6	9.8	114.3	3.6
114.3 x 5	13.5	114.3	5
114.3 x 6.3	16.8	114.3	6.3
139.7 x 5	16.6	139.7	5
139.7 x 6.3	20.7	139.7	6.3
139.7 x 8	26	139.7	8
139.7 x 10	32	139.7	10
168.3 x 5	20.1	168.3	5
168.3 x 6.3	25.2	168.3	6.3
168.3 x 8	31.6	168.3	8
168.3 x 10	39	168.3	10
193.7 x 5	23.3	193.7	5
193.7 x 5.4	25.1	193.7	5.4
193.7 x 6.3	29.1	193.7	6.3
193.7 x 8	36.6	193.7	8
193.7 x 10	45.3	193.7	10
193.7 x 12.5	55.9	193.7	12.5
193.7 x 16	70.1	193.7	16
219.1 x 5	26.4	219.1	5
219.1 x 6.3	33.1	219.1	6.3
219.1 x 8	41.6	219.1	8
219.1 x 10	51.6	219.1	10
219.1 x 12.5	63.7	219.1	12.5
219.1 x 16	80.1	219.1	16
219.1 x 20	98.2	219.1	20
244.5 x 6.3	37	244.5	6.3
244.5 x 8	46.7	244.5	8
244.5 x 10	57.8	244.5	10
244.5 x 12.5	71.5	244.5	12.5
244.5 x 16	90.2	244.5	16
244.5 x 20	111	244.5	20
273 x 6.3	41.4	273	6.3
273 x 8	52.3	273	8
273 x 10	64.9	273	10
273 x 12.5	80.3	273	12.5
273 x 16	101	273	16
273 x 20	125	273	20
273 x 25	153	273	25
323.9 x 6.3	49.3	323.9	6.3
323.9 x 8	62.3	323.9	8
323.9 x 10	77.4	323.9	10
323.9 x 12.5	96	323.9	12.5
323.9 x 16	121	323.9	16
323.9 x 20	150	323.9	20
323..9 x 25	184	323.9	25
355.6 x 8	68.6	355.6	8
355.6 x 10	85.2	355.6	10
355.6 x 12.5	106	355.6	12.5
355.6 x 16	134	355.6	16
355.6 x 20	166	355.6	20
355.6 x 25	204	355.6	25
406.4 x 10	97.8	406.4	10
406.4 x 12.5	121	406.4	12.5
406.4 x 16	154	406.4	16
406 x 20	191	406.4	20
406.4 x 25	235	406.4	25
406.4 x 32	295	406.4	32
457 x 10	110	457	10
457 x 12.5	137	457	12.5
457 x 16	174	457	16
457 x 20	216	457	20
457 x 25	266	457	25
457 x 32	335	457	32
457 x 40	411	457	40

SHS Square Hollow Section Sizes

Square Hollow Sections (SHS)

SHS Size	Weight (kg./m)	Height (mm)	Width (mm)	Wall Thickness (mm)
20 x 20 x 2	1.1	20	20	2
20 x 20 x 2.5	1.3	20	20	2.5
25 x 25 x 2	14	25	25	2
25 x 25 x 2.5	1.7	25	25	2.5
25 x 25 x 3	2	25	25	3
30 x 30 x 2	1.7	30	30	2
30 x 30 x 2.5	2.1	30	30	2.5
30 x 30 x 3	2.5	30	30	3
40 x 40 x 2.5	2.9	40	40	2.5
40 x 40 x 3	3.4	40	40	3
40 x 40 x 3.2	3.6	40	40	3.2
40 x 40 x 3.6	4	40	40	3.6
40 x 40 x 4	4.4	40	40	4
40 x 40 x 5	5.3	40	40	5
50 x 50 x 2.5	3.7	50	50	2.5
50 x 50 x 3	4.4	50	50	3
50 x 50 x 3.2	4.6	50	50	3.2
50 x 50 x 3.6	5.1	50	50	3.6
50 x 50 x 4	5.6	50	50	4
50 x 50 x 5	6.9	50	50	5
50 x 50 x 6	8	50	50	6
50 x 50 x 6.3	8.3	50	50	6.3
60 x 60 x 2.5	4.5	60	60	2.5
60 x 60 x 3	5.3	60	60	3
60 x 60 x 3.2	5.6	60	60	3.2
60 x 60 x 3.6	6.3	60	60	3.6
60 x 60 x 4	6.9	60	60	4
60 x 60 x 5	8.4	60	60	5
60 x 60 x 6	9.9	60	60	6
60 x 60 x 6.3	10.3	60	60	6.3
60 x 60 x 8	12.5	60	60	8
70 x 70 x 3	6.2	70	70	3
70 x 70 x 3.2	6.6	70	70	3.2
70 x 70 x 3.6	7.4	70	70	3.6
70 x 70 x 4	8.2	70	70	4
70 x 70 x 5	10	70	70	5
70 x 70 x 6	11.8	70	70	6
70 x 70 x 6.3	12.3	70	70	6.3
70 x 70 x 8	15	70	70	8
80 x 80 x 3	7.2	80	80	3
80 x 80 x 3.2	7.6	80	80	3.2
80 x 80 x 3.6	8.5	80	80	3.6
80 x 80 x 4	9.4	80	80	4
80 x 80 x 5	11.6	80	80	5
80 x 80 x 6	13.6	80	80	6
80 x 80 x 6.3	14.2	80	80	6.3
80 x 80 x 8	17.8	80	80	8
90 x 90 x 5	13.1	90	90	5
90 x 90 x 6	15.5	90	90	6
90 x 90 x 6.3	16.2	90	90	6.3
90 x 90 x 8	20.1	90	90	8
100 x 100 x 3.6	10.8	100	100	3.6
100 x 100 x 4	11.9	100	100	4
100 x 100 x 5	14.7	100	100	5
100 x 100 x 6	17.4	100	100	6
100 x 100 x 6.3	18.2	100	100	6.3
100 x 100 x 8	22.6	100	100	8
100 x 100 x 10	27.4	100	100	10
120 x 120 x 4	14.4	120	120	4
120 x 120 x 5	18	120	120	5
120 x 120 x 6	21.2	120	120	6
120 x 120 x 6.3	22.2	120	120	6.3
120 x 120 x 8	27.6	120	120	8
120 x 120 x 10	33.7	120	120	10
120 x 120 x 12	39.5	120	120	12
120 x 120 x 12.5	40.9	120	120	12.5
140 x 140 x 5	21	140	140	5
140 x 140 x 6	24.9	140	140	6
140 x 140 x 6.3	26.1	140	140	6.3
140 x 140 x 8	32.6	140	140	8
140 x 140 x 10	40	140	140	10
140 x 140 x 12	47	140	140	12
140 x 140 x 12.5	48.7	140	140	12.5
150 x 150 x 5	22.6	150	150	5
150 x 150 x 6	26.8	150	150	6
150 x 150 x 6.3	28.1	150	150	6.3
150 x 150 x 8	35.1	150	150	8
150 x 150 x 10	43.1	150	150	10
150 x 150 x 12	50.8	150	150	12
150 x 150 x 12.5	52.7	150	150	12.5
150 x 150 x 16	65.2	150	150	16
160 x 160 x 5	24.1	160	160	5
160 x 160 x 6	28.7	160	160	6
160 x 160 x 6.3	30.1	160	160	6.3
160 x 160 x 8	37.6	160	160	8
160 x 160 x 10	46.3	160	160	10
160 x 160 x 12	54.6	160	160	12
160 x 160 x 12.5	56.6	160	160	12.5
160 x 160 x 16	70.2	160	160	16
180 x 180 x 5	27.3	180	180	5
180 x 180 x 6	32.5	180	180	6
180 x 180 x 6.3	34	180	180	6.3
180 x 180 x 8	42.7	180	180	8
180 x 180 x 10	52.5	180	180	10
180 x 180 x 12	62.1	180	180	12
180 x 180 x 12.5	64.4	180	180	12.5
180 x 180 x 16	80.2	180	180	16
200 x 200 x 5	30.4	200	200	5
200 x 200 x 6	36.2	200	200	6
200 x 200 x 6.3	38	200	200	6.3
200 x 200 x 8	47.7	200	200	8
200 x 200 x 10	58.8	200	200	10
200 x 200 x 12	69.6	200	200	12
200 x 200 x 12.5	72.3	200	200	12.5
200 x 200 x 16	90.3	200	200	16
220 x 220 x 6	40	220	220	6
220 x 220 x 6.3	41.9	220	220	6.3
220 x 220 x 8	52.7	220	220	8
220 x 220 x 10	65.1	220	220	10
220 x 220 x 12	77.2	220	220	12
220 x 220 x 12.5	80.1	220	220	12.5
220 x 220 x 16	100	220	220	16
250 x 250 x 5	38.3	250	250	5
250 x 250 x 6	45.7	250	250	6
250 x 250 x 6.3	47.9	250	250	6.3
250 x 250 x 8	60.3	250	250	8
250 x 250 x 10	74.5	250	250	10
250 x 250 x 12	88.5	250	250	12
250 x 250 x 12.5	91.9	250	250	12.5
250 x 250 x 16	115	250	250	16
260 x 260 x 6	47.6	260	260	6
260 x 260 x 6.3	49.9	260	260	6.3
260 x 260 x 8	62.8	260	260	8
260 x 260 x 10	77.7	260	260	10
260 x 260 x 12	92.2	260	260	12
260 x 260 x 12.5	95.8	260	260	12.5
260 x 260 x 16	120	260	260	16
300 x 300 x 6	55.1	300	300	6
300 x 300 x 6.3	57.8	300	300	6.3
300 x 300 x 8	72.8	300	300	8
300 x 300 x 10	90.2	300	300	10
300 x 300 x 12	107	300	300	12
300 x 300 x 12.5	112	300	300	12.5
300 x 300 x 16	141	300	300	16
350 x 350 x 8	85.4	350	350	8
350 x 350 x 10	106	350	350	10
350 x 350 x 12	126	350	350	12
350 x 350 x 12.5	131	350	350	12.5
350 x 350 x 16	166	350	350	16
400 x 400 x 8	97.9	400	400	8
400 x 400 x 10	122	400	400	10
400 x 400 x 12	145	400	400	12
400 x 400 x 12.5	151	400	400	12.5
400 x 400 x 16	191	400	400	16
400 x 400 x 20	235	400	400	20

RHS Rectangular Hollow Section Sizes

Rectangular Hollow Sections (RHS)

RHS Size	Weight (kg./m)	Height (mm)	Width (mm)	Wall Thickness (mm)
50 x 25 x 2.5	2.7	50	25	2.5
50 x 25 x 2.5	2.7	50	25	2.5
50 x 25 x 3	3.2	50	25	3
50 x 30 x 2.5	2.9	50	30	2.5
50 x 30 x 3	3.4	50	30	3
50 x 30 x 3.2	3.6	50	30	3.2
50 x 30 x 3.6	4	50	30	3.6
50 x 30 x 4	4.4	50	30	4
50 x 30 x 5	5.3	50	30	5
60 x 40 x 2.5	3.7	60	40	2.5
60 x 40 x 3	4.4	60	40	3
60 x 40 x 3.2	4.6	60	40	3.2
60 x 40 x 3.6	5.1	60	40	3.6
60 x 40 x 4	5.6	60	40	4
60 x 40 x 5	6.9	60	40	5
60 x 40 x 6	8	60	40	6
60 x 40 x 6.3	8.3	60	40	6.3
80 x 40 x 3	5.3	80	40	3
80 x 40 x 3.2	5.6	80	40	3.2
80 x 40 x 3.6	6.3	80	40	3.6
80 x 40 x 4	6.9	80	40	4
80 x 40 x 5	8.4	80	40	5
80 x 40 x 6	9.9	80	40	6
80 x 40 x 6.3	10.3	80	40	6.3
80 x 40 x 8	12.5	80	40	8
90 x 50 x 3	6.2	90	50	3
90 x 50 x 3.2	6.6	90	50	3.2
90 x 50 x 3.6	7.4	90	50	3.6
90 x 50 x 4	8.2	90	50	4
90 x 50 x 5	10	90	50	5
90 x 50 x 6	11.8	90	50	6
90 x 50 x 6.3	12.3	90	50	6.3
90 x 50 x 8	15	90	50	8
100 x 50 x 3	6.7	100	50	3
100 x 50 x 3.2	7.1	100	50	3.2
100 x 50 x 3.6	8	100	50	3.6
100 x 50 x 4	8.8	100	50	4
100 x 50 x 5	10.8	100	50	5
100 x 50 x 6	12.7	100	50	6
100 x 50 x 6.3	13.3	100	50	6.3
100 x 50 x 8	16.3	100	50	8
100 x 60 x 3	7.2	100	60	3
100 x 60 x 3.2	7.6	100	60	3.2
100 x 60 x 3.6	8.5	100	60	3.6
100 x 60 x 4	9.4	100	60	4
100 x 60 x 5	11.6	100	60	5
100 x 60 x 6	13.6	100	60	6
100 x 60 x 6.3	14.2	100	60	6.3
100 x 60 x 8	17.5	100	60	8
120 x 60 x 3.6	9.7	120	60	3.6
120 x 60 x 4	10.7	120	60	4
120 x 60 x 5	13.1	120	60	5
120 x 60 x 6	15.5	120	60	6
120 x 60 x 6.3	16.2	120	60	6.3
120 x 60 x 8	20.1	120	60	8
120 x 60 x 10	24.6	120	60	10
120 x 80 x 3.6	10.8	120	80	3.6
120 x 80 x 4	11.9	120	80	4
120 x 80 x 5	14.7	120	80	5
120 x 80 x 6	17.4	120	80	6
120 x 80 x 6.3	18.2	120	80	6.3
120 x 80 x 8	22.6	120	80	8
120 x 80 x 10	27.4	120	80	10
140 x 80 x 4	13.2	140	80	4
140 x 80 x 5	16.3	140	80	5
140 x 80 x 6	19.3	140	80	6
140 x 80 x 6.3	20.2	140	80	6.3
140 x 80 x 8	25.1	140	80	8
140 x 80 x 10	30.6	140	80	10
150 x 100 x 4	15.1	150	100	4
150 x 100 x 5	18.6	150	100	5
150 x 100 x 6	22.1	150	100	6
150 x 100 x 6.3	23.1	150	100	6.3
150 x 100 x 8	28.9	150	100	8
150 x 100 x 10	35.3	150	100	10
150 x 100 x 12	41.4	150	100	12
150 x 100 x 12.5	42.8	150	100	12.5
160 x 80 x 4	14.4	160	80	4
160 x 80 x 5	17.8	160	80	5
160 x 80 x 6	21.2	160	80	6
160 x 80 x 6.3	22.2	160	80	6.3
160 x 80 x 8	27.6	160	80	8
160 x 80 x 10	33.7	160	80	10
160 x 80 x 12	39.5	160	80	12
160 x 80 x 12.5	40.9	160	80	12.5
180 x 100 x 4	16.9	180	100	4
180 x 100 x 5	21	180	100	5
180 x 100 x 6	24.9	180	100	6
180 x 100 x 6.3	26.1	180	100	6.3
180 x 100 x 8	32.6	180	100	8
180 x 100 x 10	40	180	100	10
180 x 100 x 12	47	180	100	12
180 x 100 x 12.5	48.7	180	100	12.5
200 x 100 x 4	18.1	200	100	4
200 x 100 x 5	22.6	200	100	5
200 x 100 x 6	26.8	200	100	6
200 x 100 x 6.3	28.1	200	100	6.3
200 x 100 x 8	35.1	200	100	8
200 x 100 x 10	43.1	200	100	10
200 x 100 x 12	50.8	200	100	12
200 x 100 x 12.5	52.7	200	100	12.5
200 x 100 x 16	65.2	200	100	16
200 x 120 x 6	28.7	200	120	6
200 x 120 x 6.3	29.9	200	120	6.3
200 x 120 x 8	37.3	200	120	8
200 x 120 x 10	45.9	200	120	10
200 x 120 x 12	54.5	200	120	12
200 x 120 x 12.5	55.7	200	120	12.5
250 x 150 x 5	30.4	250	150	5
250 x 150 x 6	36.2	250	150	6
250 x 150 x 6.3	38	250	150	6.3
250 x 150 x 8	47.7	250	150	8
250 x 150 x 10	58.8	250	150	10
250 x 150 x 12	69.6	250	150	12
250 x 150 x 12.5	72.3	250	150	12.5
250 x 150 x 16	90.3	250	150	16
260 x 180 x 6	40	260	180	6
260 x 180 x 6.3	41.9	260	180	6.3
260 x 180 x 8	52.7	260	180	8
260 x 180 x 10	65.1	260	180	10
260 x 180 x 12	77.2	260	180	12
260 x 180 x 12.5	80.1	260	180	12.5
260 x 180 x 16	100	260	180	16
300 x 200 x 5	38.3	300	200	5
300 x 200 x 6	45.7	300	200	6
300 x 200 x 6.3	47.9	300	200	6.3
300 x 200 x 8	60.3	300	200	8
300 x 200 x 10	74.5	300	200	10
300 x 200 x 12	88.5	300	200	12
300 x 200 x 12.5	91.9	300	200	12.5
300 x 200 x 16	115	300	200	16
350 x 250 x 6	55.1	350	250	6
350 x 250 x 6.3	57.8	350	250	6.3
350 x 250 x 8	72.8	350	250	8
350 x 250 x 10	90.2	350	250	10
350 x 250 x 12	107	350	250	12
350 x 250 x 12.5	112	350	250	12.5
350 x 250 x 16	141	350	250	16
400 x 200 x 6	55.1	400	200	6
400 x 200 x 6.3	57.8	400	200	6.3
400 x 200 x 8	72.8	400	200	8
400 x 200 x 10	90.2	400	200	10
400 x 200 x 12	107	400	200	12
400 x 200 x 12.5	112	400	200	12.5
400 x 200 x 16	141	400	200	16
450 x 250 x 8	85.4	450	250	8
450 x 250 x 10	106	450	250	10
450 x 250 x 12	126	450	250	12
450 x 250 x 12.5	131	450	250	12.5
450 x 250 x 16	166	450	250	16
500 x 300 x 8	97.9	500	300	8
500 x 300 x 10	122	500	300	10
500 x 300 x 12	145	500	300	12
500 x 300 x 12.5	151	500	300	12.5
500 x 300 x 16	191	500	300	16
500 x 300 x 20	235	500	300	20

Pro Tip

For exposed architectural HSS, specify ASTM A1085 instead of A500 Grade B. A1085 has tighter dimensional tolerances and guaranteed minimum wall thickness - A500 allows 10% negative tolerance, meaning a “1/2 inch” wall could legally be 0.45”. For columns and exposed members where appearance and consistent properties matter, A1085 is worth the premium.

Common Mistake

Welding HSS corners without proper fit-up and preheat. The corners of RHS and SHS are cold-worked during forming, creating residual stresses that can cause cracking if welded without adequate preparation. Preheat according to thickness and steel grade, and use low-hydrogen electrodes to minimize hydrogen-induced cracking.

Field Note

When drilling or cutting openings in HSS columns, avoid placing holes near corners - the cold-worked corner material is more susceptible to fatigue cracking. Keep penetrations at least 2x wall thickness away from corners, and always reinforce large openings with plates or sleeves per your structural engineer’s details.