Lifting Slings

Oops. That should read: If a welded chain is not grade stamped, a responsible engineer would NOT consider it stronger than 'proof coil grade 30' at best.
Reply to
David Merrill
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I agree about the in-person inspection, it makes for a vastly better HF experience. Even then I've had a couple odd surprises on the positive side where an item on display was apparently an older version of the product and the item in the crate turned out to be a newer and nicer version when I got it home. I haven't had a reverse case yet.
As for the sling ratings, if you see the item in person it may well list the appropriate standards. The HF ads very often don't describe the item fully.
Pete C.
Reply to
Pete C.
Guys, thanks for all this great information. Just what I needed. Also, it finally motivated me to do a Google search - DUH! So, here is some info on the specific slings that Enco has on sale:
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Check out the "Tuff-Edge Slings" description *.pdf and the "General Information on Web Slings" *.pdf. Looks like a class act, ASTM references, 3/16-inch thickness polyester, application advice.
Given this information, Iggy - is that Harbor Freight "1 TON CAPACITY LIFTING SLING" for $9.99/ea really only .03-inch thick as stated at
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?
I also found that
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on catalog page 1352, offers slings for prices lower than the Enco sales price.
Looks like, for my steadying purposes (see details of my reply to Steve B), I would probably be adequately served by a two 1" x 6' single-ply slings. These can be wrapped multiple times around the machine part if shorter length is called for. Several of the 1-inch width eye loops should (translation = 'I hope') fit in my crane's slip hook. The four load leveler chains, slip hooks, lifting nuts, and 3/4" threaded rod will be doing the primary lifting for the lathe. I will re-evaluate when I finally settle on a milling machine.
David Merrill
Reply to
David Merrill
I am not home right now, but I thought that it was thicker than that. 0.03 inch is 3/4 mm, I would think that it is closer to 2-3mm of thickness.
Reply to
Ignoramus22371
Bench lathe and stand are separate; lathe weighs 1000 lb. Several on the yahoo 12x36importlathes group report having handled these successfully (slowly and using care) with the shop crane.
If shipping material is not appropriate to the task, I plan to move it down the lawn and across a crushed stone patio to my walk-out basement door on a toboggan-skid constructed of 4x4's atop 1/2" plywood with turned up front edge. It will be pulled by a JD lawn/garden tractor with a hand-held tether rope at the rear end to aid in steering and provide some braking if needed on the 7/40 downslope.
David Merrill
Reply to
David Merrill
Our 50 tonne crane uses perhaps 3/4" chain for overhead lifting. While the dies are lifted with four chains, only two are ever fully loaded, and they take some pretty (very!) aggressive shock loads sometimes. I've never even heard of one breaking.
Regards,
Robin
Reply to
Robin S.
"David Merrill" wrote
If you do it this way, use a "basket loop." You can google to see one. Basically, you are hooking one eye to the hook, going around the machine (sometimes more than once) and bringing the second eye back to the hook.
Don't use a choker setup unless you absolutely have to. More chance of breakage, and it comes down really tight on the load. The basket lift will be the strongest, yet gentlest on your load. A choker is when you pass the web through the eye, and have only one eye hooked to your lifting eye. Even if you have to use a short piece of chain to make up the shortage, use a shackle on both ends of the chain.
Basket, don't choke.
Steve
Reply to
Steve B
We've had some hoist rings pull out for various reasons. They typically hit the roof if they were under full load (about four stories up) with the chains attached. *Kinda* dangerous!
Sometimes people don't hook up the dies right and one hook comes off. That's a pretty amazing sight. 15 - 50 tons of die flapping around. Leaves a hellova dent in whatever's underneath.
Regards,
Robin
Reply to
Robin S.
Well, I can tell a very recent (November 2006) war story:
When I was taking delivery of the Millrite, which weighs 1,200 pounds, I used a towtruck (rented with driver from a local gas station) to pick the mill out of the bed of the 3/4-ton truck that brought the mill, put it down on the ground. A towtruck and some slings is how the mill got into the 3/4-ton truck as well.
The original plan was to put the dangling mill through the doorway opening using the towtruck boom, thus clearing the threshold, but the straps stretched too much, and it wasn't even close to fitting. So, we took the head off the mill (200 or 300 pounds, four 5/8-inch bolts), and put the machine base through the opening using the boom.
Attaching the machine base to the towtruck hook was a trick. What (only just) worked, was a 6' double-eye strap wrapped twice around the base in a choke hold just under the flange to which the head attaches.
This was too close for comfort. I plan to make a lifting plate that bolts to the headless base for future moves. I also got some flanged eye bolts and T-slot nuts so I can bolt these eyes to the table T-slots and securely lift the table off the mill, should it become necessary.
The machine head was moved into the basement on a little 4-wheel wooden dolly, and reinstated on the base using two 3-foot endless slings, a quick-link, some chain, and an engine hoist rented from the local Taylor Rentals. The problem was that the hoist couldn't go lower than about 24", so the lift had to be done in two steps. First from dolly onto some cribbing, shorten chains between hook and quick-link holding the slings, then lift up to the low ceiling, just clearing the top of the machine base.
One thing to be aware of is that slings (or chains) pulled tight to reduce headroom can pull sideways out of a lifting hook, abruptly dropping the load, so I use a large shackle or quick-link to ensure that this cannot happen. MSC carries suitable slings, alloy shackles and quick-links.
The 3' endless slings are made by Lift-All (type EN1-801D), are made and tested to a recognized standard, and are marked with their load limits. Cost $16 each from MSC. I didn't use heavier slings because they are too stiff and hard to use for such a small load as this.
As for lifting equipment in general, if the manufacturer does not explicitly specify a safe working load, the item is for decoration only. Do not use it for hoisting. Period. This excludes the vast majority of stuff found in hardware stores.
Joe Gwinn
Reply to
Joseph Gwinn
I've moved a lot of Bridgeports in my time. The easiest way is to slide a timber under the head, approach with a fork lift from the front, with a fork on each side of the head. The machine is perfectly balanced, and won't tip over since the majority of the weight is below the lifting point.
Reply to
Dave Lyon
Get yourself a collection of Unistrut brackets, nuts, bolts, 1/2" all thread lengths and sections of Unistrut. You'll find them indispensable for a while lot of rigging, including things like a Bridgeport.
Pete C.
Reply to
Pete C.
It's a good approach, but it wouldn't have worked in this case, because the doorway into my basement is too narrow (35") for the head to go through sideways.
Joe Gwinn
Reply to
Joseph Gwinn
[snip]
Good idea. I'll have to see what loads the manufacturer guarantees, especially in bending. I've seen some pretty stout unistrut.
As for the lifting plate for the millrite base, that sounds like a good millrite project. Use 1-inch plate, and who needs to compute stresses.
Joe Gwinn
Reply to
Joseph Gwinn
I've lifted my Bridgeport using two pieces of the deep (2"?) Unistrut run under the ram in front of and behind the column and resting on top of my forklift forks on either side of the column. I only picked the Bridgeport up about an inch for safety and moved slowly, but there was no sign of the slightest strain on the Unistrut.
Pete C.
Reply to
Pete C.
And this adds what to the discussion? I mean, what "worthwhile" information is added?
dennis in nca
Reply to
rigger
Nothing at all. And, for the record, my local hardware store _does_ have chain rated for lifting, in stock. But again, mueller is certainly meeting expectations.
Reply to
Dave Hinz
The message is: When working with chains for lifting, don't follow Ignorant's advice to use any chain, but only certified chains. The same with slings. But you knew that.
Nick
Reply to
Nick Mueller
The name's not "Ignorant." Iggy has never advised anyone to "follow" his advise on chains. Why are you making up these lies?
For the adults in the group: Selecting and using chains certified for overhead lifting, especially for the industrial purchaser, is a good idea. The less personal control you have over lifting equipment the more abuse resistant they should be. And rigging materials can take a terrible beating. Anyone with more than a few months of industrial experience knows what I mean.
On the other hand, for those of you who have direct control over the materials and methods of rigging (and for those who need to delegate this responsibility) I offer the following: To insure your chain's "weakest link" is safe requires: 1. Frequent inspection and 2. Proper rigging methods.
When you inspect your chain it's important to inspect each link, individually. One "fast and dirty" way to do this is to measure links for lengthening and welds for distortion and cracking. We used a sheet metal go/no-go gauge when measuring links, with elongation information supplied by the manufacturer, any chain with links drawn thin beyond the "safe zone" were immediately cut-up and discarded. I'd suggest this inspection be done at least weekly in a busy shop.
The inspection for damaged welds (on a well cleaned chain) takes longer and should be done by an experienced person (or an outside service), rather than the newest hire. Welds won't generally be damaged by tension alone but can easily be damaged by improper usage such as using a chain for a heavy lift while a link is bearing on a sharp hard edge. Placing a softener under the chain at this type of stress point should be "standard procedure" in all shops. A "softener" can be as simple as a heavy piece of carpet, or a 2x4, or as complex as a steel framework over 1" thick felt depending on your requirements.
Why do I use ordinary non-certified lifting chain in my shop? Because it's not required, and here's why: 3/8"- grade 80 lifting chain is rated at 7,100#. 3/8"- grade 30 (we used to call this "plow" chain) not certified for lifting is rated at 2,650# The heaviest lift I may encounter in my shop is 1000#. Also, should I encounter any weight approaching this weight I always use a "basket" and one or more chains which will raise lifting levels by 2 to 4 times the rating of the individual chain. Do I feel this method is safe? 100%. Why do I feel safe??? INSPECTION. This is THE most important thing I can stress. A chain rated grade 120 can be less reliable than a grade 30 "If it has not been inspected thoroughly." The softer, lower grades of chain are naturally more subject to deformation so I'd suggest inspecting these after every heavy "pick."
My suggestion for everyone: Monday morning: Inspect those chains!
dennis in nca
Reply to
rigger

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