STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

Md Waqquar Ahmad · SEFI Member Joined: 04 Aug 2009 Posts: 15

Respected Sir,
As per IS 800:2007 the minimum thickness of steel is not specified, Please let me know what is the minimum thickness and what is the minimum size of steel section (Angle, ISMC, ISNT,ISHT,ISST, ISLT,ISJT,ISMB,ISSC,ISHB) is being practiced in India.
As in the steel table (IS 808) there are some smaller section also which are not being used.

And i Also want to know that is SP 38 new Edition is available in market , which is as per New Code IS 800:2007.

The reason behind this is that i am doing my final year Mtech Structure Project in steel, if SP 38 as per new code is not available in market i will try do it with new Code. If you have any suggestion regarding the same feel free to give it to me it will make me proud.

Thanking you in Anticipation,

sspawar · ... Joined: 05 Jun 2009 Posts: 1196

Dear Mr. Ahmed,
As per latest catlouge(Nov 2008) and my knowledge -SP38-1987 is still active. Further new edition is not issued from BIS.
I am pasting here a list of Codes related to the Stru Sections mainly 801 and 811 is partaing to the light section.

Str Sections.
No.      - Standard Description     Reaffirmed     No. of Amd.
1     IS 808 : 1989 Dimensions for Hot Rolled Steel Beam, Column, Channel and Angle Sections     2004     1
2     IS 811 : 1987 Cold formed light gauge structural steel sections     2004

arulsteel · General Sponsor Joined: 26 Jan 2003 Posts: 68

Dear Mr.Waqquar Bhai
Happy to know your interest in IS:800(2007). Yes the minimum thickness restrictions have been removed in the new code - however a chapter has been added on durablity. The minimum thickness must be decided based on the exposure condition of the steel structures and also based on the aggressive nature of the environment. The normal rule is that if steel is put in an enclosure away from diurnal wetting and drying, there is no need for mimimum thickness requirements.
You have a happy news that SP:38 is not available and please go ahead and produce one of your own using the new IS:800(2007). Please share it with us so that we can even have a document which may be published by BIS after a peer review process. Waqquar Bhai! good effort go ahead! Inshah Alla make it in your PG dissertation. Tata Structura is developing a document something similar to SP:38 but dedicated to tubular sections. This work is being pursued at IIT Madras. Tata Structura may make that publication free. In case of doubts please be in touch or send a mail to Prof.Satish at kim@iitm.ac.in (kim@iitm.ac.in) regarding the work on tubular trusses.
regards
arul(serc)

From: Md Waqquar Ahmad <forum@sefindia.org>
To: general@sefindia.org
Sent: Sunday, 13 September, 2009 1:54:55 PM
Subject: [SEFI] Minimum Size & Thickness of Steel Section

Respected Sir,
As per IS 800:2007 the minimum thickness of steel is not specified, Please let me know what is the minimum thickness and what is the minimum size of steel section (Angle, ISMC, ISNT,ISHT,ISST, ISLT,ISJT,ISMB,ISSC,ISHB) is being practiced in India.
As in the steel table (IS 808) there are some smaller section also which are not being used.

And i Also want to know that is SP 38 new Edition is available in market , which is as per New Code IS 800:2007.

The reason behind this is that i am doing my final year Mtech Structure Project in steel, if SP 38 as per new code is not available in market i will try do it with new Code. If you have any suggestion regarding the same feel free to give it to me it will make me proud.

Thanking you in Anticipation,

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Md Waqquar Ahmad · SEFI Member Joined: 04 Aug 2009 Posts: 15

Thank you Sir for giving me valuable information as well as appreciating my effort.
after completing i will share it to you all for the review.
Thanks Again .

Dr. N. Subramanian

Dear Er. Ahmed and Er Pawar,

BIS is Govt. organization and it took more than 20 years to bring out new editions of IS 800:2007(earlier version 1984), and also IS 456:2000(earlier version 1978). How can you expect them to update all other codes, so quickly. There are many other codes and Handbooks, which are related to IS 800, such as IS 802, IS 806, SP 38, SP 1-5, SP 40, etc., We can only pray God for them to be revised. As far as I know, the work on revising these codes and Hand books have not been started. I believe revision work on IS 801 has started. My friend Dr Arul of SERC can through some light on it.

BIS will sell the old versions(Even ACI sells ACI 318-05, even now), as it will get revenue. These codes and Handbooks have also become very expensive!

Best wishes
Subramanian

Dr. N. Subramanian

Dear Er Waqquar Ahmad,

This is a good question. Many novice engineers specify steel sections based on their design, which are often not available in practice. It is better if you write to Sail and Tata Steel to get the steel sections rolled by them. My book Appendix A(available in CD) contains the available sections*I, channel, equal and unequal angles, and Tees) in the market. It also includes properties of Wide flange sections, Castellated beams, Circular tubes and hollow sections and cold rolled lipped channel and Zed sections.

Though the minimum thickness of steel provision is removed to allow the use of cold formed sections, proper painting/coating has to be used. They are found in the Durability section of the code.

Best wishes for your project,
Subramanian

SUCHA SINGH · SEFI Member Joined: 14 Jul 2009 Posts: 18

Dear SAFIANS,
For the latest on revisions and other updating programmes of BIS one may visit BIS website www.bis.org.in.
THanks and regards
SUCHA SINGH

hiren_patel · SEFI Member Joined: 30 Aug 2017 Posts: 5

Hello Sefians, I wanted to know that is there any minimum thickness requirement that we have to satisfy to design a PEB structural sections apart from limiting width-to-thickness ratio given in table 3 of IS800. As in practice, economy plays major role in reducing and deciding thickness of members instead of codal provisions. So, is there any guidance or restriction or good practice to follow to get the confusion solved??

vikram.jeet · General Sponsor Joined: 26 Jan 2003 Posts: 3365

I think , SP 38 is not revised and is based on WSM and still active as enlightened by Er Pawar & Dr NS sir .

Minimum thickness of members is very important for durability of steel members , and prescribed maintenance standards ( periodic painting schedule) are generally not adhered causing rusting / deterioration

Exposure conditions of steel members must be kept in view . In Certain situations where maintenance & inspection is not very easy , eg steel pressure shafts in HYDROPOWER structures , Corrosion allowance is additional thickness to be added to design thickness..

vikram.jeet · General Sponsor Joined: 26 Jan 2003 Posts: 3365

Codal provisions need to be adhered and cannot be hindsighted for economy considerations .

Yes a design engineer always wish to create economical design but DESIGN IS NATIONAL , though analysis is Universal. It has to be done respecting the Country Codal requirements.

In case National Code is silent on certain provision , specialist literature or foreign Codes can always be referred for better and logical design. All tender documents generally incorporate such situations where National Code provisions are silent on certain aspect .