Steel grade selection?

[MrZukerman]

I'm looking at building a set of pallet forks and also a grapple for my SSQA loader, and have been looking at buying but just can,t justify the cost when i can build it myself. Plus it is something to due, anyway is most people using normal mild steel, or something stronger? I know a few company built ones say they use a higher grade steel so they can go thinner wall to keep wight down, just curios of everyone's thoughts?

 

[bjr]

What are you lifting? True pallet forks are made of high quality steel. mild steel pallet forks would be a waste of time to build. I think Northern tool sell forks and you can mount them however suit you. bjr

 

[MrZukerman]

I have a "real" set of forks I picked up from a old forklift. I was referring to building the frame or mounting system for them i guess you would call it.

 

[Brad_Blazer]

I think bale spears are the least expensive high-strength forks unless you can get a deal on something at a scrap yard.
Agri Supply - Search Results for spear

The lift capacity of forklilfts is typically more than 3x the capacity of a CUT loader. You don't necessarily need that much strength but real forks are nice for their thinness, taper, and durability.
Here are the ones at Northern - note the 4000lb capacity and the price tag.
Atlas Forklift Forks — 4,000-Lbs., 42 in. | Replacement Forks | Northern Tool + Equipment

To calculate the point load at the tip of a fork that will cause the metal to yield,
Load = (yield strength)*(width)*(thickness squared)/(6*(length))
If you were to make a fork out of 4"x1.5" x 48" hot-rolled mild steel with a yield stress of 36,300psi, the end load at yield is 1134lb. Actually you have to subtract half of the 82lb weight of the fork from that value which brings it to about 1093lb. By the way, a new piece of steel that size will cost a lot more than a bale spear.

Edit - I was away for a while in the middle of this response - didn't notice your clarification. For the frame, mild steel should be fine but if higher strength is available at a reasonable price go for it. I tend to use whatever I can get for scrap price or less.

 

[Spudland_Dave]

I have a "real" set of forks I picked up from a old forklift. I was referring to building the frame or mounting system for them i guess you would call it.

If you have ISO forks you can buy just the "carrier frame" fairly cheap. 80% of the cost of a set of pallet forks are the actual forks.

I'm all about building over buying, but sometimes it just doesnt make financial sense to build...

 

[mwb]

I made a frame for the kind of forks that hook on top and bottom (probably the type you have). Not sure what size loader or tractor you have...

The frame is mostly 2 x 2 x 0.25 wall square tube except for the top member; the top piece is 1/4 inch angle - this allows clearance for the forks to slide and also spaces the tractor side high enough to build the SS attachment. If you are using a one piece QA plate then this may not be necessary.

I built it for a Kubota L3400 and it is very light and also keeps the forks as close as possible to the pins (minimize reach). I don't have pics of it but I will be seeing the tractor this weekend.:licking:

 

[countrybumpkin]

MWB just curios if you use standard mild steel or a higher grade to build your fork frame in the above post? This is the type of design I'm looking at doing for my kubota that I just finished a SSQA for. I have a set of class II forks like the ones you were talking about. How well has the frame held up for you also?

 

[fortyseven2n]

I can tell you for a fact that the notched bars that the forks ride on for Kubota forks are made from A36 hot rolled steel.

The company I work for used to machine these bars for another company that supplied Kubota.

There is an upper bar with a several notches and a lower bar with one large notch.

One was made from 5/8" x 4" and the other from 7/8" x 4" A36.

There was an angle milled on one side also.

 

[countrybumpkin]

Ok thanks for the good info.

 

[mwb]

MWB just curios if you use standard mild steel or a higher grade to build your fork frame in the above post? This is the type of design I'm looking at doing for my kubota that I just finished a SSQA for. I have a set of class II forks like the ones you were talking about. How well has the frame held up for you also?

Just found this, sorry for the late reply. I used standard "off the rack" steel. For the he 0.5 flat bar for the fork carrier I used hot rolled. The flat bar does not extend very far above the frame - it would take a lot to bend that.

A real forklift has a much higher capacity than your average CUT; I have used mine to the maximum capacity of the loader all the time and have not had a problem. If you have a 65 HP machine with a huge loader capacity then maybe you want to re-engineer this. If you have easy access to better steel then you might as well use it; just remember that you have to be able to work with it and weld it.