Steel: A History of Strength. A Future of Possibilities.

Canadian Institute of Steel Construction

   

Frequently Asked Questions

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Hollow Structural Sections Questions

HSS - ASTM A500
Are HSS produced in accordance with ASTM Specification A500 grade C equivalent to HSS meeting CSA Standard G40.21 grade 350W (or 50W in the Imperial system)?

HSS or pipe?
Can I substitute HSS with pipe in a structural application? When I go on a site, are there visual cues than can help me determine whether I am looking at round HSS structural type members or pipes?  - R.M.

HSS Truss Connections
I am detailing the connections of an HSS truss submitted by the engineer who wants to have the branch members of the truss welded directly to the chords. However, when I check the ranges of validity as proposed by Packer and Henderson, I end up needing either to provide a gap or an overlap with eccentricities at the joint to respect that wish. Should those eccentricities have been taken into account by the engineer at the design stage? - E.D. 

Seam Strength of HSS
I am trying to find information about the mechanical properties of the weld seam in hot-formed hollow structural sections without much success. Can you help? – M.C.

Big Tubes
I’ve received several questions on large tubular sections, 508 mm (20”) diameter or larger, so I thought I would group them in one big three-part question and answer.

HSS - G40.21 Class C vs A500 Grade C
Is there any relationship between Class C sections of CSA Standard G40.21 and grade C material of ASTM specification A500?

Curved steel
My query is about the design of a 5m long HSS arched member of a canopy with a 1m vertical. Can we design it simply as if it was a straight member, i.e. a beam column? Are there other methods to design this type of vertical curved member? Any references you can point me to? – S.M.

HSS - Grade C or H
Should I specify Class H or Class C, CSA Standard G40.21, 350W?

HSS - G40.21 1992 vs 1987
What is the difference between the 1987 and the 1992 editions of CSA Standards G40.20, with respect to wall thickness tolerances for hollow structural sections?

Some recent questions

COR-TEN(TM) Steel as a Facade Element
I am interested in using Cor-TenTM steel to replace some facade elements in a multi-storey building that I am renovating. Is it difficult to obtain such steels? What different types are there? I just went by the new McGill School of Music, which has a complete wall element that uses Cor-tenTM steel. It has a nice rich golden colour. Will it more or less stay that colour? — J.-C. B.

Field Welding of a HSS Beam
For adding a support structure that allows us to hang a scoreboard in an existing sports centre, one engineer suggested we weld an HSS beam directly onto the flange of a fairly large W column. However, we are now working with another engineer that questions this practice. I am an architect and would like to know if we need to be concerned? - B.G.

Reinforcement of Steel Columns
Our firm will be involved in modernizing a hospital. The building is in steel and we have to reinforce the existing columns for seismic rehabilitation and increased gravity loads due to additional floors. Unfortunately, we have found very little literature on the subject of steel column reinforcement under load. Do you know of a good source of references? - P.M.

Missing ULC Rating
I am an architect and want a fire-protection solution that provides a 1-hour rating on a W460x52 edge beam connected to a HSS203x203 column. I can find 4-hour, 3-hour and 2-hour rating values for a combined gypsum board and steel girder assembly but cannot get a 1-hour rating for this manufacturer. What are my alternatives? - R.M.