D Hook Hitch Shackle

[Bayou Boy]

Who has the best price on them?

I get them at a local oilfield supply place here. They have them in stock and the tax offsets the shipping. I think Quadratec carries them though.

 

[teotwaki]

I get them at a local oilfield supply place here. They have them in stock and the tax offsets the shipping. I think Quadratec carries them though.

Thanks! My Google search turned up UK sources but not these guys.

http://www.quadratec.com/products/product_search.php?kw=shackle

 

[ntsqd]

.....
Most people are using a class III hitch pin, which is typically a 5/8" pin made from C1018. This steel is not particularly strong, roughly 60 ksi yield and 5/8" pin has about 0.31 sq-in of area. It's better to use a 5/8" grade 8 bolt, which is 150 ksi. BTW, ksi short for thousands of pounds per square inch, so 120 ksi is 120,000 lbs/sq-in. The rule I remember is to take 50% of ultimate yield in tension and that is your ultimate shear yield. So a 5/8" hitch pin will yield at about 9300 lbs, where as a grade 8 bolt will yield in shear at just over 23,000 lbs.

A great resource for this type of info is Matweb. Where you're doing critical (i.e. Life Dependent) calcs you'll want to consult other sources too.

Cold Drawn 1018: YTS = 53.7ksi
(YTS = Yield Tensile Strength)

304 Stainless: YTS = 31.2ksi

Estimating Shear at 50% of YTS is low, but that is the safe & conservative side to be on.

FWIW a SHCS is both stronger and more Ductile than a G8 bolt. If the socket head is an issue & you wish to stay with a hex head bolt then I would use a F911 bolt as they have similar performance numbers to that of SHCS'.

It would be nice to get a bolt with the right length of unthreaded shoulder so that it has a nice smooth metal to metal interface with the shackle bracket.

It's hard b/c they aren't really sold that way, but if you buy the bolt by it's shoulder length you can then use a washer or two to make sure that the nut does not bind on the end of the threads. SAE bolt shoulder lengths are slightly inconsistant. This need for spacing is exactly what drove the design & mfg of AN washers. Can then cut the threaded section down to 2.5-3 diameters.

Hopefully this info will be of some value to someone.