How in the heck did that happen

[MossRoad]

Wow, that's some bent bolts.

 

[ponytug]

Well, you can either use stronger bolts, and risk damage the plate, or just keep changing them.
Just for comparison a coarse thread 5/8" x11 bolt is specified as follows

Grade Proof load
2 12,400lb
5 19,700lb
8 27,100lb

So, if you moved to a grade 8, it would double the strength, but then the wear might be on your Q/A plate, which is probably more expensive than the bolt. If you went to ultrastrength Lamalloy would get you to 32,750lb...

All the best,

Peter

 

[MossRoad]

.... Well, you can either use stronger bolts, and risk damage the plate, or just keep changing them.
....

That's a very good point. Sort of like shear pins on brush hogs. Except, what if it shears when you have a load up high in your bucket or forks?

 

[ponytug]

Dear MR,

I agree with you that the risks from shearing one isn't quite like a standard shear pin.

Then again, ernemats' don't appear to be shearing under load, just bending. Woodlandfarms...well Carl can let us know if the bolt actually came out under load.

All the best,

Peter

That's a very good point. Sort of like shear pins on brush hogs. Except, what if it shears when you have a load up high in your bucket or forks?

 

[woodlandfarms]

No clue on when it broke. Noticed it on startup. But. I wish I had taken a picture of the break.

It appeared it was cracked over time, then finally twist sheared off. The inside had a sort of bright twist section and the outside of the break was a bit darker. Maybe I will o dumpster diving.

I am impressed by the bending. I am not sure of the grade of bolt but I replaced it with jus a number 2

 

[MossRoad]

Power Trac: the industrial strength bolt bender. Now available in red or green.

 

[brin]

Wow ! I have never bent a pin or bolt like that...and I have done some rough logging, dirt and rock moving and other things over the years...That took a lot of force or those bolts and pins are really soft...

 

[SpringHollow]

I am amazed that i have not bent things up moving 16' x 24" logs. I cringe at each bump up and down. The shock force has to be huge. Maybe even worse when using the backhoe.

Ken

 

[MossRoad]

You ever see that video of me moving the huge tree chunk with my PT425 and the rear end off the ground? Gotta wonder what the forces are on a little 1500 pound machine moving 800 pounds around with the rear half of the machine hanging from two ball joints actually is.

 

[tcreeley]

Stress cracks/break. Same as when you bend a piece of wire back and forth until it snaps off. In my mini-backhoe I do this to the bottom pin on a regular basis. Mine bends, then snaps. A loose fit increases the possibility. I figure as someone else said, better the pin than the bushings or mount. For my backhoe I just buy a rod of cold rolled mild steel, cut the length and drill it for pins on the end, and use it until it starts to bend. If I am smart- I have a replacement ready!

Extra play increases the stress, use grease.