Carbon Steel Square Tube Size Chart: Sizes, Weights & Specifications

Carbon steel square tubes, also known as Square Hollow Sections (SHS), are widely used in structural construction, machinery manufacturing, infrastructure, and general fabrication due to their high strength-to-weight ratio, excellent weldability, and cost-effectiveness. They are available in a broad range of outside dimensions, wall thicknesses, lengths, and material grades to meet different engineering requirements.

This guide provides standard carbon steel square tube dimensions in both metric and imperial units, together with wall thicknesses, theoretical weights, dimensional tolerances, and common supply specifications to help engineers, fabricators, and purchasers compare available sizes efficiently.

What Is a Carbon Steel Square Tube?

A carbon steel square tube (SHS) is a hollow structural section with a square cross-section, manufactured from carbon steel . Unlike round steel pipes specified by schedule numbers, square tubes are designated by their outside dimensions (width × width) and wall thickness.

Square tubes are typically formed from steel coil and welded from the inside to form their shape. Common manufacturing processes include:

● Cold-formed welded (most common)
● Seamless (available for selected sizes)

They are used for structural and mechanical purposes, including building construction, equipment frames, railings, sign posts, and heavy infrastructure projects.

Standard Square Tube Size Chart

Imperial Sizes (ASTM A500)

Imperial sizes are primarily used in the North American market and are commonly manufactured to ASTM A500 Grade B and Grade C specifications for structural hollow sections.

Size (in)	Wall Thickness (in)	Weight (lbs/ft)	Standard Length (ft)
1/2 × 1/2	0.063	0.38	20 / 24
3/4 × 3/4	0.063	0.61	20 / 24
1 × 1	0.063	0.83	20 / 24
1 × 1	0.125	1.35	20 / 24
1 1/2 × 1 1/2	0.063	1.27	20 / 24
1 1/2 × 1 1/2	0.125	2.21	20 / 24
1 1/2 × 1 1/2	0.188	3.05	20 / 24
1 1/2 × 1 1/2	0.250	4.42	20 / 24
2 × 2	0.063	1.69	20 / 24 / 40
2 × 2	0.125	3.06	20 / 24 / 40
2 × 2	0.188	4.33	20 / 24 / 40
2 × 2	0.250	5.41	20 / 24 / 40
3 × 3	0.125	4.76	20 / 24 / 40
3 × 3	0.188	6.89	20 / 24 / 40
3 × 3	0.250	8.81	20 / 24 / 40
3 × 3	0.375	12.17	20 / 24 / 40
4 × 4	0.125	6.46	20 / 24 / 40 / 48
4 × 4	0.188	9.45	20 / 24 / 40 / 48
4 × 4	0.250	12.21	20 / 24 / 40 / 48
4 × 4	0.375	17.27	20 / 24 / 40 / 48
4 × 4	0.500	21.63	20 / 24 / 40 / 48
6 × 6	0.188	14.56	20 / 24 / 40 / 48
6 × 6	0.250	19.02	20 / 24 / 40 / 48
6 × 6	0.375	27.48	20 / 24 / 40 / 48
6 × 6	0.500	35.24	20 / 24 / 40 / 48
8 × 8	0.250	25.82	20 to 48
8 × 8	0.375	37.69	20 to 48
8 × 8	0.500	48.45	20 to 48
10 × 10	0.250	32.60	20 to 48
10 × 10	0.375	47.90	20 to 48
10 × 10	0.500	62.20	20 to 48
12 × 12	0.250	39.43	20 to 48
12 × 12	0.500	76.07	20 to 48
12 × 12	0.625	93.34	20 to 48
16 × 16	0.375	78.52	Up to 60
16 × 16	0.500	103.30	Up to 60
16 × 16	0.625	127.36	Up to 60

Metric Sizes (EN 10219 / GB/T 6728)

Metric square tube sizes are widely used throughout Europe, Asia, Australia, and international engineering projects. These products are commonly manufactured to EN 10219 (cold-formed) or EN 10210 (hot-finished), GB/T 6728, and AS/NZS 1163 standards

Size (mm)	Wall Thickness (mm)	Weight (kg/m)	Standard Length (m)
20 × 20	2.0	1.05	6
20 × 20	2.5	1.25	6
25 × 25	2.0	1.36	6
25 × 25	3.0	1.89	6
30 × 30	2.0	1.68	6
30 × 30	3.0	2.40	6
40 × 40	2.0	2.30	6 / 8
40 × 40	3.0	3.30	6 / 8
40 × 40	4.0	4.20	6 / 8
50 × 50	2.0	2.90	6 / 8
50 × 50	3.0	4.30	6 / 8
50 × 50	4.0	5.50	6 / 8
50 × 50	5.0	6.60	6 / 8
60 × 60	3.0	5.20	6 / 8
60 × 60	4.0	6.70	6 / 8
60 × 60	5.0	8.10	6 / 8
60 × 60	6.0	9.50	6 / 8
75 × 75	3.0	6.64	6 / 8 / 12
75 × 75	5.0	10.51	6 / 8 / 12
80 × 80	4.0	9.20	6 / 8 / 12
80 × 80	6.0	13.20	6 / 8 / 12
100 × 100	3.0	9.00	6 / 8 / 12
100 × 100	5.0	14.40	6 / 8 / 12
100 × 100	6.0	17.00	6 / 8 / 12
100 × 100	8.0	21.40	6 / 8 / 12
120 × 120	4.0	14.10	8 / 12
120 × 120	6.0	20.70	8 / 12
150 × 150	5.0	22.60	8 / 12
150 × 150	6.0	26.46	8 / 12
150 × 150	8.0	34.62	8 / 12
150 × 150	10.0	42.33	8 / 12
200 × 200	6.0	35.88	12 / 15
200 × 200	10.0	58.03	12 / 15
200 × 200	12.5	71.07	12 / 15
250 × 250	8.0	60.30	12 / 15
250 × 250	12.5	91.90	12 / 15
300 × 300	10.0	90.20	12 / 15
300 × 300	12.5	110.31	12 / 15
300 × 300	16.0	138.96	12 / 15
400 × 400	12.5	151.00	12 to 18
400 × 400	16.0	189.00	12 to 18
500 × 500	12.5	189.00	12 to 18

Dimensional Tolerances

Manufacturing tolerances ensure dimensional consistency and interchangeability for structural fabrication. The exact allowable deviations depend on the applicable manufacturing standard.

Item	ASTM A500	EN 10219
Outside Dimensions	±1% (or ±0.020", whichever is greater)	±1%
Wall Thickness	±10%	±10%
Straightness	1/8 in per 5 ft	0.2% of total length
Squareness (Corners)	90° ± 1.5°	90° ± 1.5°
Mass Tolerance	-3.5%	-3.5%

Standard Specifications & Materials

Carbon steel square tubes are available in a variety of material grades and manufacturing standards.

Parameter	Specification
Product Type	Welded Square Hollow Section (SHS), Seamless (selected sizes)
Outside Dimensions	10 × 10 mm to 500 × 500 mm (custom sizes available)
Wall Thickness	0.5 mm to 25 mm
Standard Length	6 m, 9 m, 12 m / 20 ft, 24 ft, 40 ft, 48 ft (custom cut lengths available)
Material Grades	Q195, Q235, Q355, ASTM A500 Grade A/B/C, ASTM A36, S235, S355
Manufacturing Standards	ASTM A500, ASTM A513, EN 10219, EN 10210, JIS G3466, GB/T 6728
Surface Finish	Black, Oiled, Pickled, Hot-dip Galvanized, Primer Painted
End Finish	Plain Ends, Deburred Ends, Cut to Length
Inspection	Visual, Dimensional, Mechanical Testing, Chemical Analysis (upon request)
Certification	Mill Test Certificate (EN 10204 3.1), Third-party Inspection Available
Packaging	Steel Strapping, Bundles, Waterproof Packing, Export Seaworthy Packaging

Frequently Asked Questions:

Q1: What are the standard sizes of carbon steel square tubes?
A: Standard metric sizes range from 10 × 10 mm to 500 × 500 mm. Imperial sizes range from 1/2 × 1/2 in to 22 × 22 in. Wall thickness varies by size and standard .

Q2: What is the standard length of carbon steel square tubing?
A: Metric products are typically 6 m, 9 m, or 12 m. Imperial products are commonly 20 ft, 24 ft, 40 ft, or 48 ft. Custom cut lengths are available from most manufacturers .

Q3: What wall thicknesses are available?
A: Wall thickness typically ranges from 0.5 mm to 25 mm, depending on tube size and applicable standard. Larger sections are generally produced with thicker walls for higher structural strength .

Q4: What are the most common manufacturing standards?
A: The most common standards include ASTM A500 (North America), EN 10219/EN 10210 (Europe), GB/T 6728 (China), and JIS G3466 (Japan) .

Q5: How is the weight of a carbon steel square tube determined?
A: Theoretical weight is calculated based on outside dimensions and wall thickness. Standard weight tables provide quick estimates, while custom sizes require specific calculations .

Q6: Can carbon steel square tubes be supplied in custom sizes?
A: Yes. Manufacturers can provide custom lengths, wall thicknesses, and surface treatments based on project requirements.

Conclusion:

Carbon steel square tubes are available in a wide range of standard dimensions, wall thicknesses, lengths, and material grades to meet different structural and mechanical requirements. This guide provides a comprehensive reference for engineers, fabricators, and purchasers to select the appropriate square tube for their projects.

Need a size not listed above? 

Contact us for custom dimensions, lengths, and project-specific manufacturing solutions: sales@hu-steel.com