Metal strength- 1/2" AL or SS for rope wall?

[Neilk]

Good morning,

My wife wants to create a rope wall for her "yoga studio" and it requires looping rope around a 4 inch wide piece of metal that is held in the wall by the studs. Can we go with a solid 1/2in Aluminum bar or should we go with stainless? She wants something aesthetically pleasing The total length of the bar including the parts in the framework would be 8 inches (2 inches on either end in the framing).

Here is the metal info from Metals Depot

304 Stainless Steel Round (link)

304/304L Stainless Steel Round, is ideal for all applications where greater strength and superior corrosion resistance is required. 304 Stainless Round has a durable dull, mill finish that is widely used for all types of fabrication projects that are exposed to the elements - chemical, acidic, fresh water, and salt water environments.
Specifications: ASTM A276, QQS-763, T304/304L,non-polished finish
AKA: stainless rod, stainless round bar
Applications: frame work, braces, supports, shafting. axels, marine, food, etc.
Workability: Easy to Weld, Moderate Cutting, Forming and Machining.
Mechanical Properties:Brinell = 170, Tensile = 85,000 +/-, Yield = 34,000 +/-
Nonmagnetic

OR

6061 Aluminum Round (Link)

6061 Aluminum Round, is an extruded aluminum product that is very versatile and has a wide range of applications. 6061 Aluminum Round is widely used for all types of fabrication projects where lightweight and corrosion resistance is a concern.
Specifications: ASTM B221, QQA-200/8, 6061-T6511
AKA: aluminum round bar, aluminum rod
Applications: braces, supports, trim, shafts, ornamental, pins, dowels
Workability: Easy to Weld, Cut, and Machine.
Mechanical Properties:Brinell = 95, Tensile = 45K +/-, Yield = 40K +/-

Thanks,
Neil

[aschen]

How is the loading? It is an 8" long bar, pinned at the ends with a human weight load in the middle?

[porsche4life]

Aluminum is more likely to bend. Given the short length, spend the extra and go stainless...

[vash]

i'm a visual person..i need a sketch.

what is the end use of this wall? it's decorative, but might see some load?

[widebody911]

Had to google it

[vash]

awe chit..

maybe i didnt need the visual. really?!

[jpk]

Assuming a 200 pound point load at the center of a four inch long, 1/2" diam. rod, supported at each end (simply supported beam).

The max deflection of a steel rod would be 0.003 inches. An aluminum rod would deflect about 3 times more or 0.009 inches. (assuming I got the units correct...)

[vash]

I would use regular steel. Polish it and indoors I'd bet it would stay shiny forever.


Sent via Jedi mind trick.

[Nostril Cheese]

Originally Posted by vash

I would use regular steel. Polish it and indoors I'd bet it would stay shiny forever.


Sent via Jedi mind trick.

I'd agree with this. depending on how its designed, 6061 "should" be plenty strong. Of course, I may be visualizing something different.

[porsche4life]

Originally Posted by vash

I would use regular steel. Polish it and indoors I'd bet it would stay shiny forever.


Sent via Jedi mind trick.

Thats what I was just thinking too. The ropes will help to keep it shiny too actually.

[flatbutt]

Originally Posted by widebody911

Had to google it

I need to ask...why?

[1990C4S]

Hardened and ground shaft or nickel plated steel would be strong and look right.

McMaster-Carr

[aschen]

I think JPK must have put some numbers into the bending equation, I suspect the peak stresses are quite low such that any of these materials will suffice.

In fact I think that tear out of the wood from shear will be more likely than bending failure or all or most of the proposed alloys.

[widebody911]

Originally Posted by aschen

In fact I think that tear out of the wood from shear will be more likely than bending failure or all or most of the proposed alloys.

This.

When I googled "yoga wall" I got a lot of image hits that showed the construction of reinforced walls at yogo studios

[John Rogers]

As short as the tube is, either would work fine. I would worry more about the sideways load on the wall, especially if a bunch of fat guys decide to do the bondage thing at the same time. I would hope the load is mostly straight down or close to it and I would also see if there is some sort of building code that covers this sort of insanity.

[red-beard]

304L Stainless Steel and 6061 Aluminum have a difference in strength of about 3% for the exact same size/volume. The 6061 will flex more than the Stainless Steel but it weighs about 1/3rd of the steel.

[red-beard]

We've supplied millions of pounds of 6061 aluminum for use in off-shore helicopter landing pads.

[Don Ro]

Thanks for the laughs - -
~~~~~~~
.
"maybe i didnt need the visual. really?!"
.
"I need to ask...why?"
.
"...a bunch of fat guys decide to do the bondage thing..."
.

[Porsche-O-Phile]

I'd guess the connection would fail before the cable would yield.

Connect to a structural member if possible (essentially creating a lintel). Studs might be okay if they're thick enough / spaced closely enough.

[Don Ro]

Maybe run a nicely stained & dressed 2 x 6 across the wall (or maybe two stacked atop each other)...bolted to the studs...afix the hanging bars to that?