Download annexure 7 – a.10

ANNEXURE 7 – A.10
SECTION 7
STEEL WORK
EXTRACT OF STRUCTURAL STEEL ( STANDARD QUALITY)
( Fifth Revision)
( With Amendments No. 1 to 4 )
IS : 226 – 1975
1.
Scope – Requirements for mild steel ( standard quality ) plate, sections bars. Etc.
designated as Fe 410 – S ( St 42 – S) for use in structural work. Steel may also be supplied
in copper bearing quality in which case it shall be designated as Fe 410 Cu-S(St 42 – SC).
NOTE - Steel specified in this standard is suitable for welding provided that the thickness of material does not
exceed 20 mm. When the material conforming to this standard is over 20 mm thick, special precautions may be
required in case the material is to be welded ( see IS: 823 – 1964*).
2.
Chemical Composition
Constituent
Percent. Max
Carbon ( for thickness/diameter 20mm and below)
0.23
Carbon ( for thickness/diameter over 20 mm)
0.25
Sulphur
0.055
Phosphorus
0.055
Note – When steel is required in copper-bearing quality, the copper content shall be between 0.20 and 0.35
percent.
3.
Freedom from Defects – Finished material shall be free from cracks, surface flaws,
laminations, rough, jagged and imperfect edges, etc. Minor surface defects may be
removed by grinding provided the thickness is not reduced locally by more than 4 percent (
with a maximum of 3 mm).
*
Code of procedure for manual are welding of mild steel.
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4.
4.1
Mechanical Properties
Tensile Test
Class
Plates, flats, angles,
Tees, beams, channels,
etc
Bars (round, square and
Hexagonal)
Thickness/
Diameter
mm
Tensile
Strength
kgf/mm2
Yield stress
Min.
kgf/mm2
percentage
Elongation
Min
Below 6 Bend test only shall be required
6 to 20
Over 20
Up to 40
Over 40
42 – 54
42 - 54
26
24
23
23
42 – 54
23
23
Below 10 Bend test only shall be required
10 to 20
42 – 54
26
Over 20
42 – 54
24
Note 1 – 1 N/mm2 = 1 MN/m2 = 0.102 kgf/mm2.
Note 2 – Provided that the yield stress and elongation requirements are compiled with,
The upper limit for tensile strength may be raised by 3 kgf/mm2.
Note 3 – If agreed to mutually, the material with thickness below 6 mm may be supplied
With tensile property requirements.
23
23
4.2
Bend Test – Shall withstand without cracking the prescribed test when doubled over
until internal diameter is not greater than 3 times the thickness of test piece ( 2 times
diameter in case of bars up to 25 mm diameter).
5.
Dimensions and Tolerances – Dimensions of rolled steel products shall conform to
the relevant Indian Standards as listed in Table 3 of the standard. Rolling and cutting
tolerances shall conform to IS: 1852 – 1973*.
6.
Weight – It shall be calculated on the basis that steel weighs 7.85 g/cm3.
Note – For test procedures, refer to IS: 1608 – 1972 Method of tensile testing of steel products ( first revision), IS:
1599-1974. Method for bend test for steel products other than sheet, strip, wire and tube ( first revision) and 7
and 8 of the standard.
For detailed information, refer to IS : 226 – 1975 Specification for structural steel (standard
quality) ( fifth revision).
* Specification for rolling and cutting tolerances for hot rolled steel products ( second
revision).
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