Quick links versus bolt shackles

[bluedog225]

I’m going to hang a chain hoist in a semi-permanent location. I’ve got a pretty solid mounting point in the form a 5/8”x4”x24” piece of cold rolled steel I’ll be bolting to the structure.

Coming off the steel, I was looking at bolt shackles with cotter pins as something I wouldn’t have to worry about:

A8353842-6692-4B1E-8225-530507E68CC6.jpg

but because of where I located the hole on my steel, I need to get into the 3/4” pin range to get enough room for the chain hoist hook (I wanted to leave plenty of meat under the hole). These are pretty pricey.

Pile shackles also are strangely expensive.

I was wondering if there is any reason not to use a quick link? They seem cheaper than the big shackles and still have 2-3x the safety margin I am looking for. I’d miss the reassurance of the cotter pin but I could crank it down appropriately and use “permanent” threadlocker.

And any reason not to use stainless in contact with the steel? It’s a pretty low corrosion environment.

Thanks

7CFA78CB-71F4-4CBF-B9AF-F10BC490EE5C.jpg

[mmd]

I would opt for the shackle vs. the carabiner because the weight of the lift is carried on the pin through the two legs of the shackle, whereas the carabiner puts half (or more) of the load on the threads, which are prone to corrosion cracking.

[Gib Etheridge]

You can get long "D" shackles that will (?) have room for the hook.

https://www.defender.com/product.jsp...022&id=3386031

[bluedog225]

Thanks everyone

I'm having a hard time getting comfortable with not being able to inspect those longer shackles. . I could wire them but I would still worry a bit. The first two seem safer.

[Garret]

Thanks everyone

I'm having a hard time getting comfortable with not being able to inspect those longer shackles. . I could wire them but I would still worry a bit. The first two are somewhat fail safe.

Edit-I guess the first isn't fall safe. But it's pretty robust.

?? Stainless safety wire through the hole & around the shackle covers that.

[Peerie Maa]

You can get long "D" shackles that will (?) have room for the hook.

https://www.defender.com/product.jsp...022&id=3386031

Thanks everyone

I'm having a hard time getting comfortable with not being able to inspect those longer shackles. . I could wire them but I would still worry a bit. The first two seem safer.

Drill out the treads and fit a bolt with a lock nut, simulating the Crosby shackle.

[Canoeyawl]

Make one as long as you want.
Two straps, 4 holes, two bolts.

[bluedog225]

Interesting thought. I’m not smart enough to figure out what the safe working load would be for a diy strap.

[Canoeyawl]

About like a chainplate /Tensile strength on each side of the hole

[Ron Williamson]

Yield strength,36000 psi
Calculate the area remaining after drilling bolt holes in the side plates.
Or go to a tractor / off road store and look at a snatch block(snicker).
R

[Peerie Maa]

If you are not confident with your sums, hang three or five links of chain down each side of your beam from a thorough bolt, with a bolt through the hanging links to hook your block into. Size the chain to match the chain of the chain block as a minimum, or with links big enough to take the same size bolt/pin from the Crosby catalogue.

[bluedog225]

That would work. And drilling out the threads and replacing with a bolt as well. Thanks.

[bluedog225]

I’ve been wondering how to figure out how strong my steel bar is.

Is it the thickness (5/8”) times the distance from the hole to the edge (1 3/8”) times the width of the hole (1/2”).

On the assumption that the width of the hole is the amount of steel below the load. Though in real life, suspect the load is supported by something like a 45 degree angle of steel.

Though I shouldn’t do math in public, using 1/2” as the last dimension I get 15,468 lbs.

I would love to learn more about this type calculation.

3DA539F3-A9B9-44E8-8B2A-B509E25D024D.jpg

EBEE0B26-FC1B-4BA5-AEEC-59D97FEC0BA6.jpg

[Gib Etheridge]

That's 5/8 thick Tom, you can lift the whole barn with it. The wood it's fastened to will be the weak point. When you fasten to the wood fasten at the top leaving as much wood below the fasteners as possible.

[Ron Williamson]

Yield strength is BEFORE anything starts to happen.
Breaking strength is waaay more zombies.
R

[Gib Etheridge]

Yeah, effing zombies!. They ruin everything!

[bluedog225]

Yeah. I wish I could do the math though. It’s cheaper to buy a big piece of steel than it is to hire an engineer to tell me how to size it properly. My first piece of cold rolled. Nice stuff.

And yes, it will through bolted to the 16” beams, mostly towards the top.

Thanks all

04225426-03F0-48ED-A0B1-AC11493C8F86.jpg

[J.Madison]

Just for reference, the rated load on the stainless quick link is breaking load. The rating on the crosby shackle is safe working load which is probably 1/3-1/5 of breaking load. Big difference. I wouldn't trust a cheap stainless link with anything more than 1/5 the rated breaking load, and even then would not use it for critical lifts. The crosby shackle is proper lifting hardware, quality control and material properties are much more rigorously monitored and engineered.

[bluedog225]

Good to know and thanks. I am going with a crosby shackle.

Your comments, and MMDs comments about corrosion cracking, make the case. Sounds like it is the right tool for the job.

Interesting though that the rated breaking load for the stainless link is 45,500 lbs (the image above was cropped badly).

My primary goal is to limit the odds of catastrophic failure for a few decades of light use.

The chain hoist I ordered has overload protection set at 2000 lbs.



862DC5B4-0AD7-4AE5-888F-CA6E48E80B42.jpg

[wizbang 13]

Would this be a good place for an Amsteel frapping?

[bluedog225]

Interesting stuff. Though I can’t imagine it will have the long haul uv resistance needed for this application.

[Canoeyawl]

These are never rated for lifting

DOT will not allow them on safty chains even

[Canoeyawl]

Just for eyeball work, 1/4" wire rope is breaking at 5000 lbs.
Arguably wire rope is a far better grade of steel than you will get in bar stock, but a couple pieces of 2 x 1/4 plate with 1/2 holes (centered) will, as mentioned, probably pick up your barn.
edit: cross sectional area 1/4" dia is only 0.19635 sq. in.

[Peerie Maa]

I don't think that you could have wriggled this

862DC5B4-0AD7-4AE5-888F-CA6E48E80B42.jpg

Into the hole in this anyway.

04225426-03F0-48ED-A0B1-AC11493C8F86.jpg

[Ron Williamson]

My Crosby collection
IMG_1862.jpg

[Canoeyawl]

http://www.aerialessentials.com/product/rigging-plate/

E53DA903-095E-4C2C-98CA-D611285B9CEF.jpg

[bluedog225]

That would work. Good find.

i want this thing for no good reason.

A4180E57-2D21-43C1-8DA4-BD93D88ACD53.jpg

[Canoeyawl]

I have a box of big shackles like that you need a forklift to move them.

Out last "Beam project" used 60' lengths of w24x162 (heavy...) the tail cuts made a great work bench. All welded up I could put a 40 ton excavator boom on it to rebore the pin bushings.