the grade 8 bolts where stronger than the steel!

[lloyd430]

Well I am going to have to upgrade some of the steel on my plow. I used 1X2 1/8 wall tubing as a vertical bracket- it worked till I used the weight of the tractor as a "little" down pressure. Apparently the 7000# tractor was a little too much- it snapped clean off! I just call the local shop and they will have some 3" channel cut for me on Monday- bucket till then. Looks like my students will have a new welding project next week!

 

[Industrial Toys]

Can't tell what you were doing by the picture.

Thought you said that thing was unsinkable!

 

[lloyd430]

Its in a pile in the barn now waiting to get repaired. I just couldn't believe the bolts withheld the force and the steel snapped!

 

[KennyG]

Hard to tell exactly from the pictures but you may have some fatigue/corrosion working here.

 

[LD1]

Not really hard to believe at all if you look at the math. Look at the "area" of the steel pieces.

The perimeter of that tubing would be about 6" at 1/8" thick. But it broke where the bolt holes were, and assuming 1/2" holes (times 2) take another inch off. So 5" at 1/8" thick is only 5/8" total area.

A 1/2" bolt has an area of over 3/4", AND you have two of them. Not to mention the fact that the grade 8 bolts have about twice or better the tensile strength of the steel. So the bolts would be easily 4x's stronger than that tubing.

Channel iron should fare better but I wouldnt mount it like you have with bolts through the flange. If you insist on mounting it that way, go back to tubing but upsize it. Perhaps some 2x2 x 1/4" wall

 

[Zebrafive]

1/8" wall was too small, go bigger!

 

[PANHAPP]

Are you teaching kids to build like this?

 

[SPYDERLK]

I cant see how exactly that bolt was stressed significantly there. Looks like you could have gotten by with 5/16 Grade 8 fine thread with good washers. The smaller holes would definitely help that tubing since it appears the drilled sides are under tension/compression.
larry

 

[ishiboo]

Probably needed to weld some gussets and tie plates over that area to strengthen it.

How'd you get a Boomer 40 to weigh 7000 lbs?

 

[akraven]

What is the rusty piece???? A quick attach plate? Its hard to understand exactly how you attached a plow to that if that is what it is but 1/8" would be way undersized. Do you have any better pic's?