Knuckle boom hook

[sotc]

So according to my chart I shouldn't hang more than 6300 pounds off the end of the boom. The folks I bought the truck from had a couple shackles holding the hook on okie style. The bolt is 1 1/4" grade 8 coarse thread.

 

[Reddog]

I would think something spreading the load to outside would be much better. Thats a lot of force on the bolt and threads to keep from bending and pulling out.

 

[Reddog]

And before you say it that was my best crayon.

 

[sotc]

I wonder if there may be a shackle big enough to goclear through. IMT shows a bolt like that with 2 small plates (think trailer spring hangers) and another pin with the hook, seems odd fo sho

 

[CurSedVoyce]

And before you say it that was my best crayon.

Ahhhh you just need a crayon sharpener.. I'll see if Lilly can loan ya one

 

[Reddog]

Or something like this half hanger.

http://www.grapples.us/newpage38.htm

 

[sotc]

Now were logging!

 

[lumberjack]

What's wrong with the bolt?? Granted it needs spacers to center the hook, and I haven't ran the numbers, but I would certainly imagine it's plenty strong.

 

[SkwerI]

I have that same hook on my material handler, but swapped it out because it was too confusing for groundies. Nobody could figure out how to open it and I couldn't take the suspense of watching them try. I have a standard hook on there now, not as secure but much easier for the guys who have to open it.

I'm not seeing a big issue with the bolt.

 

[cory]

It may be strong enough but it doesn't inspire confidence as it is being used in its weakest configuration, imo. Get something more suitable like Reddog pictured above. You've got a nice machine, might as well outfit it nicely. Btw, any pics of the kboom??

Brian, lol at "the suspense."

 

[sotc]

I just put a kit in the hook as the release was missing. I hate the flap type latches.

Corey, theres some pics here

 

[cory]

Not sure how I missed that! Nice looking truck!

Uh, what is a "kit?"

 

[sotc]

Spring, thumb latch and roll pin. Hooks need to be self latching and they all need rebuilt at some point so they sell kits.

 

[cory]

Lol! I thought you meant a kit was a particular item in the hook, duh.

 

[sotc]

Haha, nope. It is really a nice hook. Rated at 15,000 pounds and swivels under load

 

[PCTREE]

Why not just add a spacer on one side so all the load is right next to the support for the bolt so very little bending force, you aren't going to shear that bolt me thinks

 

[Jack]

What's wrong with the bolt?? Granted it needs spacers to center the hook, and I haven't ran the numbers, but I would certainly imagine it's plenty strong.

Willie, if I may add my 2¢ ... gotta agree with lumberjack & PCTREE about the bolt; "I would certainly imagine it's plenty strong." And, the spacer suggestions are good, too.

However, it looks like the 'weak-point' might be at the arrows in the pic below ... looks worn and too thin. Can you put up a picture looking from the end of the bolt?

 

[sotc]

Good eye Jack, yeah, those eyes are seriously wallowed from the way the shackles loaded them but thats a short term issue thats been figured out already

 

[cory]

Re grade 8's, I have a flatbed which hauls a 9k lbs machine, and it's pintle ring is held on by 2 grade 8 bolts. Every 3 or 4 yrs, I discover one of the bolts has broken at the nut. The load is on the bolts crosswise, like on the kboom tip, instead of along the vertical axis which would be much stronger. Seeing those broken bolts 2x's made me realize they aren't bulletproof at all.

Fwiw, I recently had some welding to the ring area to beef things up and take some load off the grade 8's.

 

[lumberjack]

Thats a different application, different loading, and far smaller bolts.

 

[cory]

Essentially the same loading imo, which is why I posted it. The bolts have a 7/8" head, they aren't small.

 

[woodworkingboy]

Sorry for the derail, but thinking about hooks, I've been meaning to splice a locking hook to some three strand rope that I use with the Masdam. I remembered that I had an unused locking rope snap, any reason not to use it for that purpose, as opposed to what would be the more normal type hook for such application? I think the rope snap is rated to like 5000 lbs tensile. Thanks.

 

[treesmith]

My only reason NOT to, Jay, would be that when I'm done with my Maasdam, the quickest way to remove the rope is to simply pull it on through. With the hook spliced on the end, that wouldn't be possible.