Welding chain
SteveB
to make something up, what is the best way to weld shut a piece of chain?
As in the case of when you cut a link, and want to put it back together
again.
Is the best solution a cold shut, then run a hot bead around the stub?
I've run into this lately, and seen some chain connections that "looked"
strong, but as an old rigger, I know that looks don't mean squat. I'd like
to destructively test these and see where they did finally part.
Just like to do rigging stuff 3x the SWL, and know that when I start REALLLY
pulling on something, what's likely to happen. It's always nice to analyze
failures after the fact when no one was hurt, or nothing damaged.
TIA
Steve
dan
sci.engr.joining.welding mine and will die if we don't mount a rescue
by Mon, 9 Nov 2009 15:47:43 -0700:
>At times, like when you want to make a loop of chain, and when you just need
>to make something up, what is the best way to weld shut a piece of chain?
>As in the case of when you cut a link, and want to put it back together
>again.
>
>Is the best solution a cold shut, then run a hot bead around the stub?
>
In one of my old welding text books, they show round stock being
joined with a double bevel joint. I wouldn't trust such a connection
though.
--
Dan H.
northshore MA.
fran...123
"SteveB" <old...@depends.com> wrote in message
news:hpims6-...@news.infowest.com...
We aren't talking roller chain here.
I would imagine the new riggers would only use equipment with tags. If you
have employees probably you should do that. I think you are asking about a
loop like in a manual chain fall or hoisting apparatus.
I have had good luck with my dc tig argon and 70s6 rod. bevel so you are
sure the thing is welded solid with no missing voids. In the 5/16 size I
haven't broke any of my welds with a 5000 pound tractor and all the lift it
will provide for additional traction. Usually I use chains I bought new or
just put new slipper or grabber hooks on with the pin and split pin or
cotter pin onto a healthy link. Of course there are some weaker grades of
chain than others. And some of the tagged stuff the links are more complex
than just a rod bent in an oval. Perhaps someone else will be able to tell
you what grade of chain is too high carbon or alloy for my technique. I
don't do yanking techniques. You can be pretty sure of what you are doing
with tig. A real pro probably could with sticks. I also have some
connector links which consist of two halves which overlap with kind of like
rivet like things built in. They seem somewhat thicker than the nominal
chain size they are to splice. I know there are other kinds of splicing
links.
What do you think they use at the chain factory? electron beam welding?
Fran
TinLizziedl
says...
I would recommend a full-penetration weld. Leave enough gap between the
ends so that the arc can move from side to side, avoiding a "cold weld".
Use a ceramic backing or perhaps a piece of heavy clean copper. Flat
can be made to work, but with copper you can shape it to a closer match
to the links, giving less grinding later.
Chain is typically flash welded, but it is possible to use manual
methods. What you really need to do though, after welding, is to re-
temper the welded link. After welding, the Heat-Affected Zone (HAZ)
will be very brittle compared to the rest of the chain. Proper temper
differs with material type, so if you know that, the temperatures,
holding times, and cooldown rates can be found online in most cases.
--
Tin Lizzie
"Elephant: A mouse built to government specifications."-Lazarus Long
Stuart Wheaton
Steve, I have a friend who does theatrical rigging, including flying
performers (ala Peter Pan). He has set up a destructive testing lab,
with a 5 ton load cell, and accessories. If you wanted to make a few
samples of chain, about a foot long, with the splice in the middle, I
could send you his info. He likes using his toy to break things.
Stuart
Pete C.
How It's Made had a segment on chain production. They showed the
annealed wire being bent, what appeared to be resistance welded,
induction heat treated, quenched and proof tested all in a continuous
operation. Pretty nifty, especially the proof testing where it would
advance a short section of chain between two pull hooks and then apply a
calibrated load and measure the stretch, if good it would remove the
load, index the next section into place, test, etc. Every single link in
the chain was tested.
SteveB
"dan" <no...@privacy.net> wrote in message
news:4af8b0b6...@news20.forteinc.com...
I agree. If you can't weld an open root, then the best thing is not to.
Steve
SteveB
"fran...123" <storkenst...@cox.net> wrote in message
news:8Q2Km.2964$dc2....@newsfe20.iad...
The videos I saw they used electric current to heat the links red hot, then
the two stubs were pushed together. The chains I am referring to would not
be used in critical lifting, just in situations where maximum load would be
no more than fifty percent of SWL. I know better than to pull hard on
something you're not 300% sure of.
Steve
Steve
Private
> need to make something up, what is the best way to weld shut a piece of
> chain? As in the case of when you cut a link, and want to put it back
> together again.
best http://www.slingchoker.com/sling2/crosby/v/v145.htm#A-336
not for lifting http://www.slingchoker.com/sling2/crosby/v/v146.htm#S-249
not for lifting (IMHO these just don't look solid)
http://www.slingchoker.com/sling2/crosby/v/v144b.htm#PEAR SHAPE
see notes re pear links @ http://www.thecrosbygroup.com/html/default.htm
look in the chain & accessories section
> Is the best solution a cold shut, then run a hot bead around the stub?
This is hardware store (poor) quality stuff which may? be ok for something
like repairing (snow) tire chains, or pet dog chains, but there are better
solutions.
> I've run into this lately, and seen some chain connections that "looked"
> strong, but as an old rigger, I know that looks don't mean squat. I'd
> like to destructively test these and see where they did finally part.
>
> Just like to do rigging stuff 3x the SWL, and know that when I start
> REALLLY pulling on something, what's likely to happen. It's always nice
> to analyze failures after the fact when no one was hurt, or nothing
> damaged.
>
> TIA
>
> Steve
On the sites I work on, NO lifting is permitted with ANY chain, even tagged
and certified stuff.
Similarly NO lifting is permitted using ANY field fabricated rigging, and NO
chain hooks are permitted to be field welded onto dirt-buckets. ALL lifting
equipment must be certified (by engineer or manufacturer) and have a current
engineer's NDT inspection.
Most of the traditional uses of chain have been abandoned in favour of MUCH
better and safer materials.
Repairs on NON load bearing chains such as pet dog chains or man powered
side of a chain hoist can easily be welded with 7018. Most manufactured
chain will stretch a bit before it breaks YMMV but all bets are off for
welded product.
Load or decking chains (should be proof type) used for securing transport
loads should NEVER be welded.
IMHO welding a chain is a CRIMINALLY NEGLIGENT act as you have no control
over the task that someone else may attempt with what is now an unmarked and
hazardous product that meets no standards or quality control.
IMHO, ANY welded chain has a lawyer attached.
Good luck, YMMV
SteveB
"Private" <ple...@dont.bother> wrote in message
news:hdavs5$33o$1...@aioe.org...
I agree with all you said. But you are referring to heavy construction use
situations. I have worked in those, and know that the lifting rules are
very different there than around the house. Around the house, one is hardly
likely to put a really hard pull on anything, so just "good" equipment will
do the job. Or get you killed.
Then there's "by the book". Offshore, lifting anything by rope was
prohibited by OSHA. Yet, when we wanted to unload loose timbers or 2 x 12's
from a boat with a crane, we'd get a 1" manila line and throw a timber hitch
on it and hoist away. Of course, keeping personnel out from under the load
and swinging over the water. So long as you don't lift more than two, they
don't slip, and rope and timber hitches work great.
I've seen all kinds of creative rigging that worked for that situation, and
then overkill rigups that failed.
And yes, I thoroughly agree with and have seen your point in action about
what another person would do with something you made up, or were familiar
with using and they weren't.
Yet, with all the regs and rules, we still have failures and accidents.
Really, chains are used for very few critical applications nowadays, and
socketed steel rope is preferred. If I was rigging up something
professionally, chain would be my last choice because you have so many
failure points. If I'm using it around the house, and it's not on a machine
that I know can overload it, I do not hesitate to use it. Most of the stuff
around the house isn't like picking up a Hydril or BOP.
Steve
Private
I agree that 'if rules could make the world safe, then we would not have had
any accidents for at least 20 years.'
We have both been 'in the patch' long enough to remember the bad old days
when skin and lives were expendable and safety was always compromised for
economy or speed. Industry has discovered that accidents are much more
expensive than previously thought and current thinking does not tolerate
unsafe actions and practices. You have raised the example of hoisting
planks with ropes, and while the scaffolders still do a lot of this they are
the only trade that still does much of it, the rest of us use (and even the
scaffolders prefer as less work) certified material baskets which will
safely move in one lift what it used to take a whole crew several hours to
do by hand with a rope and pulley.
Chains were very commonly used in the past but that was before we recognized
just how often their failure was the cause of injuries and property damage.
We transitioned to cable slings which were a LOT safer but today use few of
these as nylon and Kevlar is lighter, stronger and just plain nicer to use.
They have just about eliminated hand injuries from cable jaggers and are
easy to visually inspect. They also make very good chokers (particularly
the endless loop or grommet type) and you would prefer them for hoisting
planks as they grip every bit as well (or usually much better)as a rope but
are much stronger and are certified.
It has been a lot of years since I have purchased a new chain and even the
truckers only use (very large sizes) them for very specialized purposes
(securing tracked machinery, and they have stopped using lever load binders
in favour of the screw type. Young workers no longer even know what a
'snipe' is). Most of the chain still in use is very old stuff that has been
discarded (usually broken and shortened) by the original users who are now
using better products. Flat webbing with deck winches and ratchet straps
are lighter, easier to use and safer for most applications.
It is a sad fact that we are usually safer working on big jobs for big
employers, and that we are most at risk when we are around small and
independent operators who either have never learned or don't want to work
safely. We routinely do thing with ladders around the house that would get
us fired on the job. We were taught to never waste tools that are still
usable and to 'make do with what we already have' but this too often results
in our using products and procedures that are neither efficient or safe. I
do not mean to preach or lecture the group here, but I have found and
learned a lot of good information here and wish to make some small
contribution to those who may have come here as hobbyists and who lack the
kind of formal safety training you (SteveB) and I have been exposed to.
Good luck and 'Worksafe'.
Ignoramus9270
To me, it is a no brainer -- bevel and TIG, and use at reduced load
rating afterwards. If you want to not reduce the rating, use special
chain links for connecting chains. They are not that expensive. Either
figure eight connectors, or jusk links with a side with a threaded
collar that can be opened and closed.
i
Ignoramus9270
truck, unloading a welder from his pickup, pulling an ATV etc. These
are small loads, usually not overhead, and way below any reasonable
chain's capacity.
i
Private
"Ignoramus9270" <ignora...@NOSPAM.9270.invalid> wrote in message
news:yM6dnfM8GKL-RmTX...@giganews.com...
'Good enough' works great, until it doesn't.
Small nylon slings are cheap, versatile and much nicer to use than chain.
Failures of improper chain rigging either from material failure or more
commonly by just coming unhooked, have seriously hurt far too many people
and have led to many lawsuits.
It is usually the simple stuff that bites you when you least expect it.
Good luck, and 'Worksafe'
fran...123
"Private" <ple...@dont.bother> wrote in message
> It is a sad fact that we are usually safer working on big jobs for big
> employers, and that we are most at risk when we are around small and
> independent operators who either have never learned or don't want to work
> safely. We routinely do thing with ladders around the house that would
> get us fired on the job.
Yeah, not lifting but with staging and the hand rails and the toe boards and
the like if the small guys followed the rules they would never get the job.
To top that off it is politically incorrect to crack down on the street
corners where you can get illegals or perhaps legal day workers for cash.
We were taught to never waste tools that are still
> usable and to 'make do with what we already have' but this too often
> results in our using products and procedures that are neither efficient or
> safe. I do not mean to preach or lecture the group here, but I have found
> and learned a lot of good information here and wish to make some small
> contribution to those who may have come here as hobbyists and who lack the
> kind of formal safety training you (SteveB) and I have been exposed to.
>
> Good luck and 'Worksafe'.
>
I like chain. wire rope pokes holes in you where blood comes out. The
hooks on the ends can slip or hold a particular link, works great for
pulling pricker bushes out by the roots. I have a (virtually new) tagged
piece of 5/16 with a grabber hook with device to keep it in place says good
for pulling 10,000 pounds of machinery, agricultural. I guess it isn't
tagged for overhead. If one link fails it sure isn't like a nylon product
failing or even a cable snapping the whipping action of the loose end. The
abrasion resistance of chain is petty good i.e. moving rocks or broken up
concrete slab. Sure it is safer to have an excavator with a hydraulic thumb
and sit in the cab.
Since this is a welding group I could say you probably are supposed to weld
the weld on hooks not the chain.
Fran
fran
SteveB
"Howard Eisenhauer" <how...@REMOVECAPShfx.eastlink.ca> wrote in message
news:birjf5peapph20qkq...@4ax.com...
> QWhat sized chain? You might get some pointers from the way these
> guys do it-
>
> http://www.youtube.com/watch?v=2uvOgWapG2g&feature=channel
>
> H.
What size chain? That's easy. Always use bigger chain than you need. ;'-)
Steve
SteveB
"Private" <ple...@dont.bother> wrote in message
Many a bumper has been ripped off by chains. Back when they had bumpers,
that is. Now they just rip off the back third of the car.
Steve