Question about steel strength??

[Industrial Toys]

I was in a machine shop last week and saw some forks, for use in a stone quarry that were about ten inches thick!

But I have a question about steel. Let's say mild plate steel. Does it have a grain? Is it stronger one way then another based on how it is rolled?

 

[Xfaxman]

Here are a few pictures of the Forks I had built. The fab shop built this for $400 including paint a couple of years ago. I misstated the fork size in my earlier post - my memory is failing. The forks are 4x2x.156" wall. Also the Cs to attach the forks to the tubes are on top of the tube as shown. As you can see by the photos the ends are all capped for no water, i.e. interior rust. The tips of the forks are tapered as well. I have not weighed them. They are heavy but I can pick the assembly as shown and carry it so am sure they aren't over 150 lbs. I just used bolts for tractor connection for cost reasons but I use them so much I wish I would have put standard pins in.
-------------------

I like the way they are built. :thumbsup:

Just go buy two standard pins now, and be happy!

 

[Everhard]

Jodebg - Don't know why I didn't read thru your post earlier but better late then never! I've just built and used my forks - see my posting if you haven't already:

http://www.tractorbynet.com/forums/build-yourself/329493-looking-tbnr-who-posted-their.html

Mine are currently only set up for the loader but later I'll do what Zick did (see post below) to set it up for the 3pth:

http://www.tractorbynet.com/forums/build-yourself/328811-anyone-built-set-forks-front-2.html

As far as strength is concerned check out my posting for that - I've posted photo's of the loads I've carried thus far. The "C" Channel I used is called "C3 @ 4.1" Measures 3" by just shy of 1.5".
At this point I'm quite confident they are strong enough for all the lifting I'll ask. Plus they are reasonably light, and fully adjustable. The only way I'll damage them is by pushing a tine into the ground at an angle and then driving forwards. But with a little careful operation that won't happen. For that matter if the weak point is the tine and it bends vs breaking something else on the tractor frankly for the few dollars those forks cost I'll happily make more!

E.

 

[CNC Dan]

Well then, you went down the wrong road.

It may be more likly to tip the tractor back, but to the _lift system_, same force required anywhere along the forks.

 

[oldtimer 66]

IT yes steel has a grain it effects forming/ bending as to cracking aka against the grain it also effects it's electrical properties generally alternate stampings for pole pieces there are other that can elaborate on this subject later

 

[Industrial Toys]

So I would assume that it bends easier in the direction it came out of the mill??

What about hot rolled vs cold rolled? What's the difference?

 

[oldtimer 66]

You probably cannot measure the difference in tonnage on thin materials but the real problem is cracking at let's say a 1 D bend. Cold roll because of it's hardened surface from being cold worked does not like to be bend. You can grind and or polish the formed ends to minimize the cracking before bending and or forming and or heat the part minimize cracking later

 

[Creamer]

So I would assume that it bends easier in the direction it came out of the mill??

What about hot rolled vs cold rolled? What's the difference?

Yes it is preferable to have the bend line perpendicular to the way it comes off of the mill. The elongated grain structure will bend more without breaking.
While cold rolled is slightly workhardened it is usually not significant to affect bending much. Hot rolled is typically thicker material and often has more impurities in it. Hot rolled also has some scale left over from oxidation due to it being hot in air which creates a surface condition that can lead to to cracking. I prefer to use cold rolled for bending. Also, it is best to try to stay away from a 1t bend, i.e. bend radius = the material thickness. 2t makes a lot of difference.

 

[SPYDERLK]

I may have to change my opinion! I think I will do a little more work on it first before I do so, just to be absolutely sure. (I'm stubborn!) Either way, I'll be back to either gloat or eat crow.

... -- ... Hello?

Find a competent Physics professor somewhere to help. The answer is not an opinion.
,,,larry

 

[jodebg]

Again, thanks for the headsup on this nice design.

You mentioned that you wished you had used pins.
Do the bolts offer any tightening force or only serve to lock the
c-clamps iin place? Pins would provide the same fundtion as the bolts?

What thickness steel did you use for the c-clamps?

Here are a few pictures of the Forks I had built. The fab shop built this for $400 including paint a couple of years ago. I misstated the fork size in my earlier post - my memory is failing. The forks are 4x2x.156" wall. Also the Cs to attach the forks to the tubes are on top of the tube as shown. As you can see by the photos the ends are all capped for no water, i.e. interior rust. The tips of the forks are tapered as well. I have not weighed them. They are heavy but I can pick the assembly as shown and carry it so am sure they aren't over 150 lbs. I just used bolts for tractor connection for cost reasons but I use them so much I wish I would have put standard pins in.

Picture 1 and 5 are overall views. Pics 2 &3 are close-ups of the Forks attachment to the frame and the connection for the lower 3 pt arm. Pic 4 shows the tapered end of the fork.

View attachment 419046View attachment 419047View attachment 419048View attachment 419049View attachment 419050

 

[Creamer]

What thickness steel did you use for the c-clamps?

I used 1/4" for the ears for the 3 pt attach points. I only tighten the nut on the bolts hand tight - just so I do not lose them - so know there is no clamping. I want the joints to be free to pivot.

the nuts can stick sometimes so i will be finding some pins that I can replace them with.

 

[Mace Canute]

I may have to change my opinion! I think I will do a little more work on it first before I do so, just to be absolutely sure. (I'm stubborn!) Either way, I'll be back to either gloat or eat crow.

I'm back (sorry for taking so long) and I've proven myself wrong about the forces acting on a parallelogram 3PH linage so I'm eating crow!

To LD1, I offer my full apologies for telling you that you were wrong and I also offer my full apologies to everyone else whom I implied was also wrong.

 

[LD1]

Apology accepted. Just glad to help everyone learn things and no hard feelings.

 

[AGRIMAN]

I wish that I had a dollar for every time a engineer told me something was going to work.

 

[Sodo]

I wish that I had a dollar for every time a engineer told me something was going to work.

Boeing gets dollars like that!

 

[CNC Dan]

I'm back (sorry for taking so long) and I've proven myself wrong about the forces acting on a parallelogram 3PH linage so I'm eating crow!

To LD1, I offer my full apologies for telling you that you were wrong and I also offer my full apologies to everyone else whom I implied was also wrong.

It takes a good person to admit it when they are wrong.

I'm glad it didn't come to name calling, and insults.

 

[LD1]

It takes a good person to admit it when they are wrong.

I'm glad it didn't come to name calling, and insults.

Me too. :thumbsup:

I try to keep everything friendly. I know the internet is hard to judge "tone". But I didnt get the sense that Mace was getting hostile or stooping to a lower level. So neither did I.

 

[Sodo]

A linkage scuffle has a pretty specific path if at least one party understands the physics, and can figure out what element of understanding the other guy is missing. And continues to search for that missing element.

Where theres blind leading the blind then members pick a side of the fence and tend to try to build up their coalitions. Passions can be inflamed. It can be comical and/or annoying.

I enjoyed the various ways LD1 (and others) spent their TIME to create examples guiding members toward understanding it for themselves. Makes all the time wasted seem worthwhile.

 

[Creamer]

A linkage scuffle has a pretty specific path if at least one party understands the physics, and can figure out what element of understanding the other guy is missing. And continues to search for that missing element.

Where theres blind leading the blind then members pick a side of the fence and tend to try to build up their coalitions. Passions can be inflamed. It can be comical and/or annoying.

I enjoyed the various ways LD1 (and others) spent their TIME to create examples guiding members toward understanding it for themselves. Makes all the time wasted seem worthwhile.

I agree. Even though I am an engineer i never thought a 3 PH like that before. When I read it I had to think it through a little but realized he is right. Part of that probably comes from the way he stated it - so matter-of-factly - that I had to give him the benefit of the doubt and reason it out rather than just react. This board is great for learning things!

 

[LD1]

It is not time wasted at all if only one person now understands how it works. Time would only be wasted if I (and others) failed to help someone understand.

I think anyone with a reasonable understanding of practical things can reason through a 3ph and understands how it works. Those who only react instead of taking the time to reason it out, are the ones who think of it as a simple lever. Too many years of bad advise being given, makes it a challenge to undo peoples way of thinking and to get them to take the time to think it through.

Similar enough to the whole fel bleeding down and valve vs cylinder seals discussions we have had too many times to count. It is hard to get someone to re-analyze something that is contrary to what they have believed for many years, even if it is wrong.