RHS 70x40x3.9 Açotubo · Weight & Dimensions

Açotubo, cold-formed sections · Rectangular Hollow Section

Rectangular Hollow Sections (RHS) are tubular profiles with excellent torsional resistance and aesthetic appeal. Used for columns, trusses, and exposed structural elements.

Also known as: PTR 70x40 cal 8 (México) · Caño estructural 70x40 (Argentina)

The RHS 70x40x3.9 steel profile weighs 6.0 kg/m (4.00 lb/ft), has a depth of 70 mm (2.76 in), flange width 40 mm (1.57 in). Cross-sectional area: 757.991 mm². Moment of inertia Ix = 45.167 cm⁴, Iy = 18.58 cm⁴.

Cross-section (not to scale)

Gauge equivalent: 3.9 mm ≈ 9 gauge (Manufacturers Standard Gage)

Dimensions

Property	Metric	Imperial
Depth (h)	70 mm	2.76 in
Width (b)	40 mm	1.57 in
Thickness (t)	3.9 mm	0.15 in
Fillet radius (r)	7.8 mm	0.31 in
Weight	6.0 kg/m	4.00 lb/ft

Section Properties

Property	Metric	Imperial
Area (A)	757.99 mm²	1.175 in²
Moment of inertia (Ix)	45.17 cm⁴	1.09 in⁴
Moment of inertia (Iy)	18.58 cm⁴	0.45 in⁴
Elastic section modulus (Sx)	12.9 cm³	0.788 in³
Elastic section modulus (Sy)	9.29 cm³	0.567 in³
Plastic section modulus (Zx)	16.51 cm³	1.008 in³
Plastic section modulus (Zy)	11.12 cm³	0.679 in³
Radius of gyration (rx)	2.44 cm	0.961 in
Radius of gyration (ry)	1.57 cm	0.616 in