Over the years I have lost count of how many times someone in the field or in a training session has asked me the question: “Is a shackle the same as a clevis?”
In fact, more than one person has gone a step further and let me know in no uncertain terms that the U-shaped rigging fitting with a pin that they use is a “clevis” and it will continue to be their nomenclature of choice.
After 30-plus years of hearing this debate I’m long overdue in putting to print some clarification that will hopefully satisfy individuals on both sides of the fence.
If you were to research the word “clevis” in the Webster’s and Collins English Dictionaries you would find these definitions:
Clevis — A U-shaped metal piece with holes in each end through which a pin or bolt is run, used for attaching a drawbar to a plough. (You get a farming type application from the good OLD days.)
Webster’s Dictionary
Clevis — A U-shaped metal fitting with holes in the ends through which a pin or bolt is passed in order to attach one thing to another.
Collins English Dictionary
Going by Webster’s definition you can see why a lot of individuals with a farming background have always used the word “clevis” as opposed to “shackle.”
Based on the Collins English Dictionary’s definition there are other rigging components that could come close to also matching the definitions above, such as swage sockets, spelter sockets, wedge sockets, or turnbuckle jaw end fittings.
Thus, to put a conclusion to the topic at hand (or at least my conclusion), the popular name shackle is part of the clevis family, which has many cousins, also with different names but are similar in appearance and function.
Rig Safe!
–Danny
Danny’s Rigging Den is a blog series written by Danny Bishop, Crosby’s corporate director of value added training.