Draft Indian Standard STRUCTURAL STEEL …

1 Doc:MTD 4(4885) 1 For comments only BUREAU OF Indian STANDARDS Draft Indian Standard STRUCTURAL STEEL (ORDINARY QUALITY) ICS ---------------------------------------- ---------------------------------------- ---------------------------------------- ------------------------ Not to be reproduced without the permission of Last date for receipt of BIS or used as Standard comments is 15 Nov. 2008 FOREWORD (Formal clauses will be added later) The STRUCTURAL STEEL covered under this Standard is intended for general purposes such as door and window frames, window bars, grils, STEEL gates, hand railing, building hardware, fencing post and tie bars.

2 And shall not be applicable for dynamic loading other than wind loads, , platform roofs, foot over bridges, office buildings, some member of transmission towers, other ordinary factory sheds not subjected to dynamic loading. It is not recommended to be used : i) If welding has to be employed for fabrication. ii) If the structure is situated in the earthquake zones subjected to severe damages, and iii) If the design of the structure has been based on plastic theory. Rivet bars are not covered in this Standard and are covered in IS 1148 STEEL products conforming to the requirements of this specification can be rolled from the semis conforming to IS 2831.

3 For all the tests specified in this Standard (chemical/physical/others), the method as specified in relevant ISO Standard may also be followed as an alternate method. For the purpose of deciding whether particular requirement of this Standard is complied with the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2:1960 `Rules for rounding off numerical values (revised) . The number of significant places retained in the rounded off value should be the same as that of the specified value in this Standard .

4 1 SCOPE This Draft Standard covers the requirement of low tensile STRUCTURAL STEEL (ordinary quality) such as plain round of all sizes, square of all sizes, flat bar of all sizes, angles up to 50 x 50 x 10 mm, tee section up to 100 x 100 x 12 mm, channels up to 100 x 60 x 12 mm. 2 REFERENCES The standards listed below contain provisions, which through reference in this text constitute provisions of this Standard . At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreement based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below: Doc:MTD 4(4885) 2 IS No.

5 Title 228 (in various parts) Method for chemical analysis of STEEL 808:1989 Dimensions for hot rolled STEEL beam, column, channel and angle sections (third revision) 1173:1978 Hot rolled slit STEEL tee bars (second revision) 1252:1991 Hot rolled STEEL bulb angles Dimensions (first revision) 1599:1985 Method for bend test (second revision) 1608:2005 Metallic Materials- Tensile testing at ambient temperature (third revision) 1730:1989 STEEL plates sheets, strips and flats for STRUCTURAL and general engineering purposes (second revision) 1732:1989 Dimensions for round and square STEEL bars for STRUCTURAL and general engineering purposes (first revision) 1852.

6 1985 Rolling and cutting tolerances for hot-rolled STEEL products (fourth revision) 1863:1979 Hot rolled STEEL bulb flats (first revision) 1956(in various parts) Glossary of terms relating to iron and STEEL (in various parts) 2831:2001 Carbon STEEL cast billet ingots, billets, blooms and slabs for re-rolling into low tensile STRUCTURAL STEEL (third revision) 3803(Part 1):1989 STEEL Conversion of elongation values: Part 1 Carbon and low alloy steels (second revision) 3954:1991 Hot rolled STEEL channel sections for general engineering purposes (first revision) 8910:1978 General technical delivery requirements for STEEL and STEEL products 3 TERMINOLOGY For the purpose of this Standard , the following definitions in addition to those given in the relevant parts of IS 1956 shall apply.

7 Micro-Alloying Elements Elements, such as niobium, boron, vanadium and titanium added singly or in combination to obtain higher strength to weight ratio combined with better toughness, formability and weldability as compared to unalloyed STEEL of similar strength level. Weldability A metallic substance is considered to be weldable by a given process and for the given purpose, when metallic continuity to a stated degree can be obtained by welding using a suitable procedure, so that the joints comply with the requirements specified in regard to both their local properties and their influence on the construction of which they form a part.

8 4 SUPPLY OF MATERIAL General requirements relating a supply of STRUCTURAL STEEL shall conform to IS 8910. 5 GRADES There shall be three grades of STEEL as given in Table 1 and Table 3. 6 MANUFACTURE The processes used in the STEEL making and further hot rolling into STEEL strips, sections, flats, bars, etc, are left to the discretion of the manufacturer/supplier Doc:MTD 4(4885) STEEL shall be semi-killed or killed. Rimming STEEL may be supplied by mutual agreement between the manufacturer and the purchaser. 7 FREEDOM FROM DEFECTS All finished STEEL shall be well and cleanly rolled to the dimensions, sections and masses specified.

9 The finished material shall be reasonably free from surface flaws; laminations; rough/jagged and imperfect edges and all other harmful defects. Minor surface defects may be removed by the manufacturer/supplier by grinding provided the thickness is not reduced locally by more than 4 percent below the minimum specified thickness. Reduction in thickness by grinding greater than 4 percent but not exceeding 7 percent may be made subject to mutual agreement between the purchaser and the manufacturer/supplier. Subject to agreement with the purchaser, surface defects which cannot be dealt with as in may be repaired by chipping or grinding followed by welding and inspection by a mutually agreed procedure such that: a) After complete removal of the defects and before welding, the thickness of the item is in no place reduced by more than 20 percent.

10 B) Welding is carried out by approved procedure by competent operators with approved electrodes and that the welding is ground smooth to the correct nominal thickness; and c) Subsequent to the finish grinding, the item may be required to be normalized or otherwise heat-treated at the purchaser s discretion. The material may be subjected to non-destructive testing to determine soundness of material subject to mutual agreement between the purchaser and the manufacturer. 8 CHEMICAL COMPOSITION Ladle Analysis The ladle analysis of the STEEL , when carried out by the method specified in the relevant parts of IS 228 or any other established instrumental/chemical method, shall be as given in Table 1.