Any Metallurgists Here? What specific material are Ball joint pins typically?
07-24-2019, 03:51 PM
#16
Race Car
I'm not familiar with that alloy, maybe it's wonderful.
However, 31 points of chromium gives me the heebie jeebies about the charpy notch toughness value (brittle fracture), even with 12 points of molybdenum to moderate it.
But I repeat, I have zero experience with this alloy.
The Chrome Moly steel I like for this application, like all high carbon steels, corrodes like it's trying to win a championship, so it must be galvanically protected or painted, etc. Stay away from plating for structural parts. I simply sprayed my parts with rattle can cold galvanize (which is very soft) and top coated with some rattle can epoxy. Ball joint pins will typically be grease coated, and that's enough.
However, 31 points of chromium gives me the heebie jeebies about the charpy notch toughness value (brittle fracture), even with 12 points of molybdenum to moderate it.
But I repeat, I have zero experience with this alloy.
The Chrome Moly steel I like for this application, like all high carbon steels, corrodes like it's trying to win a championship, so it must be galvanically protected or painted, etc. Stay away from plating for structural parts. I simply sprayed my parts with rattle can cold galvanize (which is very soft) and top coated with some rattle can epoxy. Ball joint pins will typically be grease coated, and that's enough.
If you would, I have one question in light of the quoted reply.
I buy these in quantity as described, I change them often after expensive lessons (body damage, loss of track time/value to fees/travel/points, etc.).
I have noticed when taking a new pair from a ziplock storage, veins or rust and/or corrosion.
Are these already compromised in expected life given the duty is equal...?
Thanks again,
T
07-24-2019, 05:34 PM
#17
Racer
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Honestly I couldn't give an educated opinion without conducting destructive testing. NDA (non destructive testing such as dye penetrant, Magna flux, X-ray inspection, etc) are good, but where safety of life is involved I prefer good old test-to-destruction.
07-24-2019, 11:11 PM
#18
Three Wheelin'
Thread Starter
Dave it has been suggested that these pins might be just Stainless? Because the pin didn't Fracture upon impact it actually Bent. Was thinking of doing a "File" check on it... what Really stinks is that I used to work for a company that had a Niton Nuclear Tester, I was able to scan anything and it would Tell me what it was , Stainless Incon 3014 /316. ect.. Inconel, Hasteloy Even Ided AL6xn.. UH...
07-25-2019, 12:04 AM
#19
Racer
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I would guess the stock pins are carburized (case hardened) mild steel. The case (probably about .060" deep) increases the wear resistance while allowing the bulk of the part to be soft and ductile. And it's a lot cheaper to make parts this way than to go through all the steps needed to correctly make parts from heat treated alloy steel.
07-25-2019, 01:54 AM
#20
Drifting
I want a Nilton Nuclear Tester! With the manual! And the schooling! And I will call Charlie at willwood racing and ask him what his pins are made of if he hasn’t gone an retired by now. The stock pins are harder then most people think. And Charlie’s are some special super super super hard pins as well. Something a regular machine shop just doesn’t have the equipment to produce. He doesn’t make any more “A-arms” AKA “Charlie Arms” but he knows what everything is made of. He’s like a metal god, next to NASA knowledge on metals and alloys and many other things I didn’t know exist. But never had I heard about a Nilton Nuclear Tester till now! I’m sure Chrlie has thou. Now I must google it.
07-25-2019, 09:25 AM
#21
Three Wheelin'
Thread Starter
I want a Nilton Nuclear Tester! With the manual! And the schooling! And I will call Charlie at willwood racing and ask him what his pins are made of if he hasn’t gone an retired by now. The stock pins are harder then most people think. And Charlie’s are some special super super super hard pins as well. Something a regular machine shop just doesn’t have the equipment to produce. He doesn’t make any more “A-arms” AKA “Charlie Arms” but he knows what everything is made of. He’s like a metal god, next to NASA knowledge on metals and alloys and many other things I didn’t know exist. But never had I heard about a Nilton Nuclear Tester till now! I’m sure Chrlie has thou. Now I must google it.
......Cant wait to Here what he has to say... 
Funny, Charlie arms, and Fabcar arms are 2 of three approved arms for PCA Club Racing... BOTH Discontinued....
07-25-2019, 10:04 AM
#22
I should see if my friends machine shop could make "Charlie Arms".
As far as identifying metals one of the engineers I work with identifies metals by smelling them.....he is kinda special....like Sheldon Cooper kinda special.
As far as identifying metals one of the engineers I work with identifies metals by smelling them.....he is kinda special....like Sheldon Cooper kinda special.
Last edited by gruhsy; 07-25-2019 at 03:03 PM.
07-25-2019, 01:31 PM
#23
Three Wheelin'
Thread Starter
Then he could have a nice sideline being a border control agent with a Sniffer like that WOW ! Make Shure you shower before work or that guy will tell the whole office..
Dave, You mentioned Chromoly.. How about Docal R8? I just built a cage out of it for a friend and MAN is that stuff tuff! I manually bend by tubing, and when compared to .120 wall DOM mild steel tube VS Docal R8 in an .095 The Docal is Stronger! I had all I could do to bend it! The Manufacturer states it is less brittle than 4130... Just Curious..
07-25-2019, 03:59 PM
#24
Burning Brakes
Thanks
Mike G.
07-25-2019, 04:36 PM
#25
Three Wheelin'
Thread Starter
All I know is that I mounted my Bender on a 4ft x 4ft welding table which is portable.. I have a 4 foot handle on it that gives me decent leverage.. I don't need to secure the table in anyway to bend 120 wall mild steel... I hold the corner of the table with my left hand and in my right the 4 foot bar. I do kinda like a chest press when bending.. One handed... The .095 wall Docal? A Resounding no... no way in hell was I going to bend it one-handed... I had to Clamp the bench to my Lift and use both hands and body weight to bend it.. After the entire cage was done I also noticed I had worn through a schedule 40 "sleeve" on the bender where the fulcrum is and It was starting to wear into the pin as well... (This is my wintertime workout) lol
07-25-2019, 08:12 PM
#29
Racer
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07-25-2019, 08:45 PM
#30
Burning Brakes
Yes. It is the yield strength that varies.
See https://en.wikipedia.org/wiki/Young%27s_modulus
See https://en.wikipedia.org/wiki/Young%27s_modulus
Thanks
Mike G.