Difference between grades of chain

[icewolf08]

You can buy rated shackles, and they should have the working load stamped right on them. Shackles are standard hardware for lifting across many industries. Generally, and I mean no offense by this, I would only buy shackles that are made in the USA. Or at least I won't buy ones that are made in China!

[derekleffew]

Originally Posted by mjw56

hhmmmm. quick links aren't rated for overhead??...

From http://www.jrclancy.com/Downloads/TFWM0708_McCauley.pdf, article written by David McCauley for Technologies for Worship Magazine:

Using Quick links instead of
Shackles to hang things from.
Quick links are not for overhead
lifting; most are not pull-tested unless
you get specially made ones that have
the WLL printed on them. One of the
most important reasons quick links
should not be used for hanging is
that if improperly installed, vibrations
from speakers or the up and down
motion of lifts can open them up.

The next paragraph happens to be about chain,

Using the wrong chain. Most
of the chain that is sold at hard-
ware stores is not made for lifting.
It has not been pull tested, and the
manufacturers state clearly that it is
not for lifting. I see the use of bent
wire chain “swing set chain” and
sub grade chain used all the time
in many applications. This should
never be done- if you decide to do
this, you will carry total responsibil-
ity if something bad happens. Even
worse, most of the time the chain
is wrapped around sharp edges like
beams that will cut the WLL at least in
half on any chain, let alone substan-
dard chain. Every link in Alloy grade
80 or 100 lifting chain is pull tested to
over the WLL by the factory. I’ve been
in the factory when chain has failed
the WLL test. It sounds like a gunshot
when it breaks. This does not happen
often, but it drives the point home
that a chain is only as strong as its
weakest link.

[Footer]

Originally Posted by icewolf08

You can buy rated shackles, and they should have the working load stamped right on them. Shackles are standard hardware for lifting across many industries. Generally, and I mean no offense by this, I would only buy shackles that are made in the USA. Or at least I won't buy ones that are made in China!

The chinese forged shackles that you get from most theatrical suppliers are not load tested. The CM ones that you can also buy from most theatrical suppliers are load rated. They also cost 4x as much, but you at least know what you are getting.

[fredthe]

Now, the question is, can you get the original installer to pay for the proper materials to re-hang the pipe, since they improperly installed it in the first place?

-Fred

[photoatdv]

Good point... they used hardware that's clearly not safe... so they should have to fix it. n reality though, unlikely it would happen without lawyers.

[LightStud]

Originally Posted by mjw56

Telling a bunch of suits/musicians "because ANSI/Astm/ASSE/I said so" doesn't usually work.

One would think it would be a more valid reason than "a bunch of anonymous posters ranging from high school kids to industry professionals with 30+ years of experience on an Internet message board told me."

[mjw56]

well having the knowledge to say " the grade 80 chain has a higher elongation coefficient and therefore will stretch more before it fails, hopefully continuing to carry the load after a shock until all personnel are safely away and it can be replaced" is a stronger reason than me, them he, she and they said so.

i have gone to a hardware/equipment rental store (Wharton hardware) around the corner from my house to get the chain shackles. i believe everything is made in USA and at least load rated. but for safety's sake ill stick to shackles only.
More bad news though. i was in the theater today, looked up and noticed the eye bolts in the beamclips are not solid forged rings, there bent..and not even welded shut.
this place just needs so much work.
does anyone have an extra 100,000$ they would like to donate

[cdub260]

Originally Posted by mjw56

does anyone have an extra 100,000$ they would like to donate

Sorry, I must have left it in my other pants.

[mjw56]

So i talked to the principal today and he assured me that all the rigging in that installation was inspected and is o.k.and that maybe the codes or standards have changed since the install was completed.(late 2005 to early 2006)

i told him i was still skeptical and that i would do a little more research and let him know the outcome.

has it ever been code complaint to install bent eye-bolts (meaning not solid forged eyes) or to install wire rope without thimbles in an overhead application?

[avkid]

Originally Posted by mjw56

So i talked to the principal today and he assured me that all the rigging in that installation was inspected and is o.k.and that maybe the codes or standards have changed since the install was completed.(late 2005 to early 2006)

Unless the principal is a rigger or mechanical engineer he's just spitting out whatever the installers told him.