What is your material specification for guard rails & hand rails? 1

[CN-EIT]

Just finished up Structures "Do's & Don'ts of HSS" webinar. The presenter made a point that A53 is more expensive than A500 due to the coating it receives and the requirement for hydrotesting. My firm and many of the drawings I have seen from other firms utilize A53 as their standard guard/hand rail material specification. The question is straight forward, what material grade are you specifying on your projects? To me, I am leaning towards switching to the A500 since I get a higher strength at a lower material cost. Of course, for those fabricators out there, is there an impact from the fabrication perspective on making the bends, corners, etc?

 

[dik]

I usually use G40.21-350W, which is 50ksi stuff that is weldable. Occasionally pipe comes up and use A53 Grade B pipe. Maybe a carryover from way back when... If using A500, I calculate section properties based on the minimum the spec allows.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[XR250]

If I even bothered to spec something, it would be A500. I think A53 is intended for pressure applications.

 

[dik]

I only ever spec gr 50, never pipe, and never A500. A lot of the work I do is spec'd by others and pipe occasionally shows up...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[XR250]

@Dik,

What did A500 ever do to you?

 

[dik]

If I can get CSA G40.21-350W, I like it... I use A500, but reduce the properties for the min sized dimensions... I don't dislike it... I prefer not to use it. Also grades B and C... the former at 46ksi... just as soon not get confused... There's little to recommend it.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JStephen]

If you design for A53-B, you can spec it as A53-B or A500 (ie, either allowed, not dual-spec material).
Pipe typically has a substantial thickness tolerance, so I don't know that it's any better than A500 in that respect, if you consider the pipe tolerances.
And I think the AISC steel tubing book is based on the minimum section properties anyway, so no adjustment needed in that case.
We use 1-1/2" A500 square tubing quite a bit too, which has some fabrication advantages.

 

[AgMechEngr]

A36 and A500 are both common. Coated steel can be bothersome for fabricators because of the fumes created while welding.

 

[CN-EIT]

I Certainly appreciate everyone's responses so far! I did speak with one of our fabricators and he mentioned if the job doesnt have high testing requirements they will usually just weld through the black lacquer coating, granted he did also mention if it comes with a galvanized coating they will grind that off (whew). Follow up question, when they order the A53, do they have to specify the coating on it or is it a mills preference whether they provide A53 with the black lacquer or galvanizing?

Additionally, I spoke with one of our mech engineers who used to be a pipe fitter and he mentioned that in terms of bends, when using A53 they commonly utilize the cast 90s instead of bending the piece; specifically, to avoid crimping the wall during the bend. It's a broader ranging question but is anyone aware of a potential disadvantage in the fabrication using A500?

 

[CN-EIT]

@JStephen
Just looking at the AISC tolerances for A53 vs A500, it looks like the A500 has tighter tolerances in both outer diameter and wall thickness.