# Need Help- Trying To Make Bucket Pins For Excavator-



## Bob V (Oct 18, 2016)

Hi,
I'm going to try to make some bucket pins for my CAT 314LCR excavator.
I called CAT-- and they told me the pins are very hard- much harder than the bushings they ride in (this was different information than I had heard!)
Anyways, I found some 4140 65mm Quenched and Tempered rod available online--it's expensive but much less than CAT charges for their bucket and other excavator pins.
-- so I was thinking of buying some of this 4140 rod stock, cutting it to length with my band saw, and drilling holes in the end for bolts to hold it in place on the machine.
Question: this material (4140 quenched and tempered rod) has a Brinnel hardness of 294 which the seller (Parker Steel) tells me is equivalent to Rockwell 28-30. --- Can I cut this stuff with my bandsaw and drill it HSS drills?
Thanks in advance,
Bob


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## JimDawson (Oct 18, 2016)

I have successfully cut Cat pins.  Use a good bi-metal blade on your bandsaw.  Slow speed and as much pressure as your saw will take.  It should drill & tap OK.  Keep the feed pressure up so it doesn't work harden.


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## FLguy (Oct 18, 2016)

I agree with Jim.


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## 4GSR (Oct 18, 2016)

I cut that stuff all the time on my 4 x 6 bandsaw.  Don't say what diameter the material is, I use a 10-14 vary tooth bimetal blade on my saw most of the time.  I cut dry with the saw in the lowest speed. 
I made a set of pins for my neighbor last year for his bucket loader.  He hasn't complained either.  Better not, I haven't billed him for them either!


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## Tony Wells (Oct 18, 2016)

That's the bread and butter of the oilfield. I would only add that if you have to turn it down, and you should to get a smooth surface, and you are using HSS on the lathe, get under the mill scale with the first cut. Besides, it's not all that hard right at the surface. But that hot roll crust can be rough on your HSS tool. By all means, if you have carbide for your lathe, use it. If you actually need a finished size of 65mm, you may want to back up an look at your plans again, unless that is TG&P rod you are buying. Most of it will come hot rolled and rough.


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## Bob V (Oct 18, 2016)

Thanks to everybody-- 
Tony, and everyone else:
It turns out the 65mm 4041 Quenched and Tempered rod is 87 bucks a foot!  
Can I just use 2.75" 4041 rod (about 15 bucks/foot), and turn it down on my lathe and drill it?  --Does it have to be Quenched and Tempered?


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## Tony Wells (Oct 18, 2016)

For that application I would not use as-rolled, or normalized. Q&T is the correct condition. That price sounds out of line. Shop around. I'd sell you all you wanted for that price.

Or look into 4340 Q&T, or even 4130 Q&T. Those will work fine, and maybe you can find something on ebay that's a decent price.


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## Bob V (Oct 18, 2016)

Thanks again, Tony,
Is that Q&T process all the way through the rod-- or is it like "case harden" (just on the surface I think!).  I'm asking so I know if I turn it on the lathe will I end up with a softer surface than the Q&T.
Thanks--


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## Tony Wells (Oct 18, 2016)

It is considered a "through hardening" treatment. Although the ASTM testing procedure calls for the hardness to be checked "mid-radius", that is, on the face of a cut piece halfway between the OD and the center. This is to ensure that the quenching temperature is held long enough (soak time) to get the bar up to temp all the way through. You can expect the piece to be a little softer in the dead center than it is near the OD, but not so close to the OD that you are getting readings in the decarb layer. That's why you usually will see a fairly deep grind mark on the OD of a bar where the hardness it tested. In the decarb layer, you will see low readings that are not truly representative of the bar's true hardness. The mid radius tests are what you will see on the MTR's, if the suppliers furnish them.


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## Bob V (Oct 19, 2016)

Wow!  A lesson in metallurgy.  Thanks Tony.  This forum is the best--


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## Bob V (Jul 16, 2020)

Well, four years later, and I'm finally getting around to replacing the bucket pins and bushings in my excavator. (BTW the old pins I was talking about replacing in 2016 at the beginning of this thread lasted about another 1200 hours--allowed me to clear 21 acres on my farm).

I never did find reasonably priced 4140 pin steel to turn on my lathe, but about two weeks ago, I found some bar steel at a local steel company that sells small "bits and scraps". They didn't have 4140.   The steel I bought is two bars, each  3 inches diameter and about 19 inches long.  It has orange paint marking the end of the bars, and their chart says this steel is either CR 8620 or  HR 1141  --which I believe are medium carbon alloy steels.  I think it is the HR 1141 because the crust on the outside was really tough to remove while turning this down to the 65mm diameter needed for the pins--so I'm thinking this might be the "hot rolled" product= HR 1141.

I got the pins made and it came out great (given my limited experience with this!). I used carbide tooling and almost all the chips were dark blue/black and smoked like hell-- but since it was working I persisted and the final product is the right dimensions etc.

---So I've finished making the pins, and I have bought new bushings and seals.  Plans are to install the new pins and bushings next week.

QUESTION: Do I need to send these pins off to get them "quenched and tempered" or "induction hardened" or "case hardened"-- or whatever process might be needed to harden this steel since it is going in a CAT 314 excavator?
Also, is there some DIY process I could do to harden the surface of these pins-- if it is needed?

Sorry for all the questions-- but a lot has happened since I first posted about this 4 years ago.
Hope this finds everyone well.
Bob


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## FOMOGO (Jul 16, 2020)

I just watched a recent Keith Fenner episode  



   where he used a product called Casenite, If I recall correctly. Looks to me like it would work for your project. Mike


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## Mitch Alsup (Jul 16, 2020)

Bob V said:


> QUESTION: Do I need to send these pins off to get them "quenched and tempered" or "induction hardened" or "case hardened"-- or whatever process might be needed to harden this steel since it is going in a CAT 314 excavator?



If you have an oxy-acetylene torch, gasses and a several gallon bucket of any kind of old oil, no.


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## middle.road (Jul 16, 2020)

Where are the pictures of this 'alleged' excavator? It would be cool to see.


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## Bob V (Jul 17, 2020)

Hi Dan,
I'll take some pics of the excavator today--it's a pretty typical CAT 314C LCR.

I got lucky-- there was a sticker on the steel bar I used to make the pins identifying it as HR 4340 HT.  This was one of the alternative steels Tony Wells recommended 4 years ago in this same thread.  The sticker also had an identifying "Heat Number" on it, so the company where I bought the steel was able to pull up their original order from Eaton Steel, with ALL the specs, heat treatment etc etc.  --much more info than I can understand.
Anyways, I'm pretty certain these pins don't need any hardening at all--since the steel was already quenched and tempered.  This explains to me why it was pretty hard to machine (at least for me!), I used carbide and almost all the chips were dark blue/black from the heat.

Thanks for all the help.  I've attached a couple pics-- the sticker that saved me and one of the pins i made--I didn't make the bushings.
Bob


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## Bob V (Jul 21, 2020)

Hi Dan,
Here's the "alleged Excavator".  A previous owner(s) beat the hell out of this machine so the exterior sheet metal is all dented.  When I got it the cab glass in the front was gone etc. etc.  It's been quite a project-- but fun too.
Bob


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## JimDawson (Jul 21, 2020)

I think that would look really good parked at my place. 

Nice!


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## middle.road (Jul 21, 2020)

Bob V said:


> Hi Dan,
> Here's the "alleged Excavator".  A previous owner(s) beat the hell out of this machine so the exterior sheet metal is all dented.  When I got it the cab glass in the front was gone etc. etc.  It's been quite a project-- but fun too.
> Bob


And it has 'The Grappler'! - those are handy when clearing for sure!
Come to think about it, that would be handy for handling all these surface plates I've got laying around.


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## Superburban (Jul 22, 2020)

JimDawson said:


> I think that would look really good parked at my place.
> 
> Nice!


Would look better at mine. The neighbors need more to complain to the county over.


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## pontiac428 (Jul 22, 2020)

Maybe not a grappler, but a thumb is probably more versatile in real world work.  Nice Tonka toy for the sandbox!


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