Need Help- Trying To Make Bucket Pins For Excavator-

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
 
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
 
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?
Click to expand...

If you have an oxy-acetylene torch, gasses and a several gallon bucket of any kind of old oil, no.
 
Where are the pictures of this 'alleged' excavator? It would be cool to see. :grin:
 
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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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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I think that would look really good parked at my place. :)

Nice!
 
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
Click to expand...
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. :grin:
 
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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