Cold Formed Steel
Property
Constituents
Steel sheet and strip are made from low-carbon, high-strength, low-alloy, and weathering steels generally containing about 0.15% and not exceeding 0.25% carbon except in the case of steels with a high manganese composition of approximately 1.25% and steels with vanadium and columbium (niobium) combinations where the carbon content can be as high as 0.30%.
Strip by definition is sheet material that is 304.8mm or less in width. Plate is made from carbon and high-strength low-alloy steels that are graded by both physical and chemical requirements.
Grade
|
EN 10025: 1993
|
BS 4360: 1986
|
|||||||
|
Grade
|
Min. Yield strength
|
Min. Tensile strength
|
Grade
|
Min. Yield strength
|
Min. Tensile strength
|
|||
|
< or = 16mm N/mm²
|
16<t< or =40 N/mm²
|
<3mm N/mm²
|
3<t< or =100 N/mm²
|
< or = 16mm N/mm²
|
16<t< or =40 N/mm²
|
< or = 100mm N/mm²
|
||
|
S275
|
275
|
265
|
430/580
|
410/560
|
43A
|
275
|
265
|
430/580
|
|
S275JR
|
275
|
265
|
430/580
|
410/560
|
43B
|
275
|
265
|
430/580
|
|
S275JO
|
275
|
265
|
430/580
|
410/560
|
43C
|
275
|
265
|
430/580
|
|
S275J2G3
|
275
|
265
|
430/580
|
410/560
|
43D
|
275
|
265
|
430/580
|
|
S355
|
355
|
345
|
510/680
|
490/630
|
50A
|
355
|
345
|
430/580
|
|
S355JR
|
355
|
345
|
510/680
|
490/630
|
50B
|
355
|
345
|
430/580
|
|
S355JO
|
355
|
345
|
510/680
|
490/630
|
50C
|
355
|
345
|
430/580
|
|
S355J2G3
|
355
|
345
|
510/680
|
490/630
|
50D
|
355
|
345
|
430/580
|
Chemical Composition
|
Quality
|
Grade
|
Chemical composition (% max)
|
|||||
|
C
|
Si
|
Mn
|
P
|
S
|
Nb
|
||
|
BS 4360 (1986)
|
43A
|
0.25
|
0.50
|
1.60
|
0.005
|
0.05
|
–
|
|
50B
|
0.22
|
0.50
|
1.50
|
0.005
|
0.05
|
0.003/0.1
|
|
|
43C
|
0.21
|
0.50
|
1.30
|
0.05
|
0.05
|
–
|
|
|
50C
|
0.20
|
0.50
|
1.50
|
0.045
|
0.045
|
0.003
|
|
|
EN 10025 (1993)
|
S275JO
|
0.18
|
–
|
1.50
|
0.04
|
0.04
|
0.009
|
|
S355JO
|
0.20
|
0.55
|
1.60
|
0.04
|
0.04
|
0.009
|
|
|
EN 10113 (1993)
|
S275N
|
0.20
|
0.40
|
0.5/1.40
|
0.035
|
0.03
|
0.05
|
|
S275N
|
0.20
|
0.50
|
0.9/1.65
|
0.035
|
0.03
|
0.05
|
|
Shapes
As universal beam and columns, structural steel can be I-beams, IPE-beams, H-beams, and HE-beams. Structural Hollow sections has been standardized on BS 4360 Grades 43C and 50C,but other grades can be supplied as well.
Thickness Designation
Steel Sheet and strip are generally identified by gauge number on manufactured products for the construction field, whereas the manufacturers if sheet and strip designate thickness by decimals of an inch (or metric equivalent). Steel sheet and strip are available in thickness ranging from 0.3048 to 5.839 mm), in widths from 0.457 to 1.372m), in silt widths down to 50.8mm, and in coils with a maximum weight of 9072kg.
Flat sheets are also available with a maximum width of 1.219m and a minimum length of 1.219m.
Flatness
Hot-rolled sheet are produced in two standards of flatness:
- commercial grade, which is roller leveled
- stretcher-leveled, which represents sheet that has been actually stretched about 1 to 2%.
Surface Finishes
Cold-rolled products usually have a dull surface texture suitable for the application of finishes such as paints, enamels, or lacquers. Depending on the end use, various degrees of freedom form surface disturbances or imperfections and special finishes can be specified.
Other Properties
Refer to mild steel property.