SHACKLES...Which One is the Strongest

If you look at The Crosby Group Web site, they should have the information you need. As far as side loading, you may have to search their catalog. I think its listed on page 80.

btw, those are metric tons listed on the link for working load limit.

They are all the same.

3090/5070

JSI > Shackles > D-Shackles > Twisted D

Reminds me of the time I was building canal walls and jetties on the islands. I used them all to make my chain slings to lift heavy bollards and stack these. Mine have all been tested and show heavy deformations, but held. The bolt slot bends, and so does the rest. They are stainless steel.

The straight one holds its form better. The circle one has been stretched and the 90 one straightened. If it helps? The steel (galvanized) ones are less beautiful but cost less and for the price, do more lifting. They also become beautifully brown in color in little time.

The ones you show I use on my sail boat - it shines and weighs less.

Oh, forgot your question. answer: monkey see, monkey do - all the same strength.

the double melt chromoly

Just make sure that, after the experiments, none of them is used for lifting.

So, is it safe to say that general consensus is: the shape is not so important as the material its built with?

The 3 you show have each a different purpose:

The narrow one is for straight in line forces. The round eye is for more movement, like swinging. And the 90 is mostly used for sails where the sail comes to the mast eye 90 degrees turned. It replaces 2 straight ones in this case.

You need to know HOW MUCH you will need it to hold.

They come in sizes for that reason.

The SS are generally slimmer in the series that you show. Call them "for entertainment".

Once you buy professional bigger Shackles the SS comes in about the same sizes as the regular steel ones.

Also they wear out with moving and degrade that way.

the experimentals by bewewewewinggg

Excellent answers.

I have a piece that already wears out due to wear and tear and saltwater. I only need to carry a load of under 300 kg.

the description of what each shape does is all news to me.

Why did I waste 4.5 years at LSUNO....I could have just asked all the questions of life here! ha ha!

Shackles are load rated.

This means, a manufacturer comes up with a design, fabricates many of them and then breaks a number of them. The average breaking load is divided by a safety factor (usually 3-5) and a RATED LOAD is thus established.

Your phrase, "the most vigorous twisting, yanking, pulling and towing" has no real meaning.

Please don't stand under anything you are lifting

Visit the website: www.rigging.com come back with real questions after you have learned something

Obviously many of the answers are not from sailors. There is no difference if there is a satisfactory margin between the working load rating and the actual use load. One can not say that each particular design has its own type of use. When you need a shackle you need a shackle quickly. You use what its available and what will hold the load in the particular arrangement of load.

Hang around a building site where cranes are in use and a lot of rigging is being done. You will see that many, if not all, the shackles are extremely over rated for the task they are used for. They range in all different configurations, but they all take their load with the users conservative use of the ratings.

Seeing the twisted shackle reminds me of twisting one inch flat bar to create a stiffer door stop on a project I worked on several years ago in a shipyard. When I asked a co-worker why he put a twist in the flat bar, his answer was that twisting the steel work hardened the piece but had to have the right amount of twist to be strong. I don't know how true that is or if it applies here but I do remember that trick being useful when angle, tubular, or other types of pieces were not available.