305x305 UC — Sizes, Dimensions & Properties

7 sizes in the 305x305 serial size group. All dimensions in mm, section properties in cm units.

Designation	Mass (kg/m)	h (mm)	b (mm)	tw (mm)	tf (mm)	A (cm2)	Ixx (cm4)	Iyy (cm4)	Zxx (cm3)	Sxx (cm3)	rxx (cm)	ryy (cm)
305x305x283	282.9	365.3	322.2	26.8	44.1	360	78,900	24,600	4,320	5,110	14.8	8.27
305x305x240	240	352.5	318.4	23	37.7	306	64,200	20,300	3,640	4,250	14.5	8.15
305x305x198	198.1	339.9	314.5	19.1	31.4	252	50,900	16,300	3,000	3,440	14.2	8.04
305x305x158	158.1	327.1	311.2	15.8	25	201	38,700	12,600	2,370	2,680	13.9	7.9
305x305x137	136.9	320.5	309.2	13.8	21.7	174	32,800	10,700	2,050	2,300	13.7	7.83
305x305x118	117.9	314.5	307.4	12	18.7	150	27,700	9,060	1,760	1,960	13.6	7.77
305x305x97	96.9	307.9	305.3	9.9	15.4	123	22,200	7,310	1,450	1,590	13.4	7.69

305x305x283 UC

Designation: 305x305x283
Serial Size: 305x305
Mass per Metre: 282.9 kg/m
Depth of Section (h): 365.3 mm
Width of Section (b): 322.2 mm
Web Thickness (tw): 26.8 mm
Flange Thickness (tf): 44.1 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 9.21
Local Buckling Ratio cf/tf: 3.65
Second Moment of Area Ixx: 78,900 cm4
Second Moment of Area Iyy: 24,600 cm4
Elastic Modulus Zxx: 4,320 cm3
Elastic Modulus Zyy: 1,530 cm3
Plastic Modulus Sxx: 5,110 cm3
Plastic Modulus Syy: 2,340 cm3
Radius of Gyration rxx: 14.8 cm
Radius of Gyration ryy: 8.27 cm
Cross-Sectional Area: 360 cm2
Buckling Parameter (u): 0.855
Torsional Index (x): 7.65
Warping Constant (Iw): 6.35 dm6
Torsional Constant (It): 2,030 cm4
Surface Area per Metre: 1.94 m2/m
Surface Area per Tonne: 6.86 m2/t

305x305x240 UC

Designation: 305x305x240
Serial Size: 305x305
Mass per Metre: 240 kg/m
Depth of Section (h): 352.5 mm
Width of Section (b): 318.4 mm
Web Thickness (tw): 23 mm
Flange Thickness (tf): 37.7 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 10.7
Local Buckling Ratio cf/tf: 4.22
Second Moment of Area Ixx: 64,200 cm4
Second Moment of Area Iyy: 20,300 cm4
Elastic Modulus Zxx: 3,640 cm3
Elastic Modulus Zyy: 1,280 cm3
Plastic Modulus Sxx: 4,250 cm3
Plastic Modulus Syy: 1,950 cm3
Radius of Gyration rxx: 14.5 cm
Radius of Gyration ryy: 8.15 cm
Cross-Sectional Area: 306 cm2
Buckling Parameter (u): 0.854
Torsional Index (x): 8.74
Warping Constant (Iw): 5.03 dm6
Torsional Constant (It): 1,270 cm4
Surface Area per Metre: 1.91 m2/m
Surface Area per Tonne: 7.96 m2/t

305x305x198 UC

Designation: 305x305x198
Serial Size: 305x305
Mass per Metre: 198.1 kg/m
Depth of Section (h): 339.9 mm
Width of Section (b): 314.5 mm
Web Thickness (tw): 19.1 mm
Flange Thickness (tf): 31.4 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 12.9
Local Buckling Ratio cf/tf: 5.01
Second Moment of Area Ixx: 50,900 cm4
Second Moment of Area Iyy: 16,300 cm4
Elastic Modulus Zxx: 3,000 cm3
Elastic Modulus Zyy: 1,040 cm3
Plastic Modulus Sxx: 3,440 cm3
Plastic Modulus Syy: 1,580 cm3
Radius of Gyration rxx: 14.2 cm
Radius of Gyration ryy: 8.04 cm
Cross-Sectional Area: 252 cm2
Buckling Parameter (u): 0.854
Torsional Index (x): 10.2
Warping Constant (Iw): 3.88 dm6
Torsional Constant (It): 734 cm4
Surface Area per Metre: 1.87 m2/m
Surface Area per Tonne: 9.44 m2/t

305x305x158 UC

Designation: 305x305x158
Serial Size: 305x305
Mass per Metre: 158.1 kg/m
Depth of Section (h): 327.1 mm
Width of Section (b): 311.2 mm
Web Thickness (tw): 15.8 mm
Flange Thickness (tf): 25 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 15.6
Local Buckling Ratio cf/tf: 6.22
Second Moment of Area Ixx: 38,700 cm4
Second Moment of Area Iyy: 12,600 cm4
Elastic Modulus Zxx: 2,370 cm3
Elastic Modulus Zyy: 808 cm3
Plastic Modulus Sxx: 2,680 cm3
Plastic Modulus Syy: 1,230 cm3
Radius of Gyration rxx: 13.9 cm
Radius of Gyration ryy: 7.9 cm
Cross-Sectional Area: 201 cm2
Buckling Parameter (u): 0.851
Torsional Index (x): 12.5
Warping Constant (Iw): 2.87 dm6
Torsional Constant (It): 378 cm4
Surface Area per Metre: 1.84 m2/m
Surface Area per Tonne: 11.6 m2/t

305x305x137 UC

Designation: 305x305x137
Serial Size: 305x305
Mass per Metre: 136.9 kg/m
Depth of Section (h): 320.5 mm
Width of Section (b): 309.2 mm
Web Thickness (tw): 13.8 mm
Flange Thickness (tf): 21.7 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 17.9
Local Buckling Ratio cf/tf: 7.12
Second Moment of Area Ixx: 32,800 cm4
Second Moment of Area Iyy: 10,700 cm4
Elastic Modulus Zxx: 2,050 cm3
Elastic Modulus Zyy: 692 cm3
Plastic Modulus Sxx: 2,300 cm3
Plastic Modulus Syy: 1,050 cm3
Radius of Gyration rxx: 13.7 cm
Radius of Gyration ryy: 7.83 cm
Cross-Sectional Area: 174 cm2
Buckling Parameter (u): 0.851
Torsional Index (x): 14.2
Warping Constant (Iw): 2.39 dm6
Torsional Constant (It): 249 cm4
Surface Area per Metre: 1.82 m2/m
Surface Area per Tonne: 13.3 m2/t

305x305x118 UC

Designation: 305x305x118
Serial Size: 305x305
Mass per Metre: 117.9 kg/m
Depth of Section (h): 314.5 mm
Width of Section (b): 307.4 mm
Web Thickness (tw): 12 mm
Flange Thickness (tf): 18.7 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 20.6
Local Buckling Ratio cf/tf: 8.22
Second Moment of Area Ixx: 27,700 cm4
Second Moment of Area Iyy: 9,060 cm4
Elastic Modulus Zxx: 1,760 cm3
Elastic Modulus Zyy: 589 cm3
Plastic Modulus Sxx: 1,960 cm3
Plastic Modulus Syy: 895 cm3
Radius of Gyration rxx: 13.6 cm
Radius of Gyration ryy: 7.77 cm
Cross-Sectional Area: 150 cm2
Buckling Parameter (u): 0.85
Torsional Index (x): 16.2
Warping Constant (Iw): 1.98 dm6
Torsional Constant (It): 161 cm4
Surface Area per Metre: 1.81 m2/m
Surface Area per Tonne: 15.4 m2/t

305x305x97 UC

Designation: 305x305x97
Serial Size: 305x305
Mass per Metre: 96.9 kg/m
Depth of Section (h): 307.9 mm
Width of Section (b): 305.3 mm
Web Thickness (tw): 9.9 mm
Flange Thickness (tf): 15.4 mm
Root Radius (r): 15.2 mm
Depth Between Fillets (d): 246.7 mm
Local Buckling Ratio d/tw: 24.9
Local Buckling Ratio cf/tf: 9.91
Second Moment of Area Ixx: 22,200 cm4
Second Moment of Area Iyy: 7,310 cm4
Elastic Modulus Zxx: 1,450 cm3
Elastic Modulus Zyy: 479 cm3
Plastic Modulus Sxx: 1,590 cm3
Plastic Modulus Syy: 726 cm3
Radius of Gyration rxx: 13.4 cm
Radius of Gyration ryy: 7.69 cm
Cross-Sectional Area: 123 cm2
Buckling Parameter (u): 0.85
Torsional Index (x): 19.3
Warping Constant (Iw): 1.56 dm6
Torsional Constant (It): 91.2 cm4
Surface Area per Metre: 1.79 m2/m
Surface Area per Tonne: 18.5 m2/t

305x305 UC — Overview

The 305x305 serial size group contains 7 sections, ranging from 96.9 kg/m to 282.9 kg/m. All sections in this group share the same nominal depth and width but differ in web and flange thickness, which affects the weight and structural capacity.

Section properties are sourced from the Tata Steel Blue Book / SCI P363. For structural design to BS EN 1993-1-1 (Eurocode 3), use these properties with the appropriate partial factors from the UK National Annex.

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Section properties from Tata Steel Blue Book / SCI P363 / BS 4-1:2005.