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Ampco vs ??

3t3d

Diamond
Joined
Nov 1, 2004
Location
WI
We are looking at some Ampco parts. Nobody else wants them.... Should that be taken as a clue?
There are NO 10 foot pole marks on these parts.

Around 18" long, +0.000" / - .001" on a lot of dimensions. 3.000" +/- .002 wide, and includes a fin, or blade the length of the part, .015" thick and .6" wide... Again tight tolerances all over...
And don't forget the radiused curves to it, all to tight tolerances..


So, we have made a few tons of 954 parts. They don't bother me at all.

1.) How much could I learn making some practice parts from 954, or something else..
To learn how to fixture a part shaped like that... Making a long, skinny, fragile fin... etc...

2.) any other metal I might want to learn on, for these parts?

3.) I haven't looked too hard yet, but so far I have only seen Ampco in round rods...
Hate to take a 3.0" ++ round and machine it down to .015" thickness...

Any advice ?.. besides RUN!!!!! RUN Away! ?

Always looking for that next job... Have to look under a few rocks to find it..

The guy who used to make these parts... Sold the shop, Retired.
I don't think He wants to talk about them.. A bit of trauma. Off for the golf course therapy.
 
We are looking at some Ampco parts. Nobody else wants them.... Should that be taken as a clue?

I'd take that as a BIG clue.
Quote way high, that way if you end up getting the job, it's not as big of a loss as it would have been. :D
 
How much of this can be done by EDM, Grinding, and HSM techniques? If not much, then run away. Or, give a quick estimate, and add a couple extra "Zero's" to it before sending out the quote. Then *maybe* it'll be worth it. :)
 
I have done allot of Ampco parts, 940 series is fairly free machining, however it bends and warps all over the place. Many of the other Ampco's are extremely brittle, I would not want to machine them down to .015 in areas with a tight tolerance. Ampco kills electrodes badly, so edm is a very last option. It wires nice, that is about it.
 
At our plant we make some dies that form/wipe stainless steel; we use some ampco 18/21/25. Type depends on the application. Which ampco alloy is called out? If it's 21 or 25 you can forget about that 0.015" fin.

Last ampco I bought was 3.00" x 5.00" x 24.00" continually cast bar.
 
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Curious.. I just talked to a Bronze sales rep, he tells me that Ampco 18 is (very) similar to 954. But Ampco is proprietary and thus twice the cost.

Any experience comparing the machinability of these two materials?

I still think that these parts should be wire EDM cut..
Might not be an 18" Z height machine in the area.

Thanks again...
 
3t, the only Ampco 18 we use is for draw pads and then only the corner blocks. It has a much lower chance to gall with SS that any other metal we've tried, even 954. I'm not sure what is "proprietary" about Ampco's alloy percentages but it does show improvement in lubricity over 954 as far as 304SS is concerned.

And yes, it is high.
 
Thanks!

Does the Ampco machine much different than the 954?

That is all I have for a reference so far... Being an "ongoing rookie"... (We all are as long as we continue to learn new stuff)
 
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Use the same tooling basically, uncoated carbide. We treat it just like 4140 except we never leave a cut "straight" because it has a tendency to "blow out". That is, we always cut from the outside of the part to half way in, feather out of the cut, begin a pass from the other side, overlap, feather out. Tools have to be dead sharp. 18 isn't so bad, 21 is, and 25 is plain nasty. Don't try to tap or ream any of it. It will grab the tap or reamer and snap it. If it needs dowels or any precision fit, burn them. We have a couple guys who are experienced with it, and to get them experience I bought the blanks oversize so they could play with the stuff. That helped a lot, they've gotten quite good at working it, but they still hate seeing it.

Oh, almost forgot, Ampco recommends (and so do I) that you stress relieve it after ever major operation. (1 hr per inch of thickness at 500 degrees, cool to room temperature) 25 doesn't wrack and warp too much, but 18 will. We milled to within 0.010, relieved, then finished.
 
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Curious.. I just talked to a Bronze sales rep, he tells me that Ampco 18 is (very) similar to 954. But Ampco is proprietary and thus twice the cost.

Any experience comparing the machinability of these two materials?

I still think that these parts should be wire EDM cut..
Might not be an 18" Z height machine in the area.

Thanks again...

Good luck on that! :D 18" is a long ways to burn!!! I would no-quote the job and be done with it myself. I have never done much more with ampco 18 (I think? maybe it was 25...) other than wear blocks, and that was a pita enough. I would hate to machine that crap and try to hold +/-.001!
 
Ampco 18 and 21 are more for anti-galling situations, it is abrasive and brittle, like mentioned earlier it's porous and blows out edges easy,chews up tooling a bit. If corners must be sharp you will have to grind it, even with very sharp tooling and careful cutting, will chip the edges. The ampco 940 series is more for heat dissipation, it has more "copper" in it and cuts similar to beryllium copper, it machines better but warps like mad, you would not use this for a wear surface.
 
I'm not sure what is "proprietary" about Ampco's alloy percentages but it does show improvement in lubricity over 954 as far as 304SS is concerned.
IIRC, Ampco's major alloy difference compared to standard 954 is a much lower limit on allowed iron.
 
We are looking at some Ampco parts. Nobody else wants them.... Should that be taken as a clue?
There are NO 10 foot pole marks on these parts.

Around 18" long, +0.000" / - .001" on a lot of dimensions. 3.000" +/- .002 wide, and includes a fin, or blade the length of the part, .015" thick and .6" wide... Again tight tolerances all over...
And don't forget the radiused curves to it, all to tight tolerances..


So, we have made a few tons of 954 parts. They don't bother me at all.

1.) How much could I learn making some practice parts from 954, or something else..
To learn how to fixture a part shaped like that... Making a long, skinny, fragile fin... etc...

2.) any other metal I might want to learn on, for these parts?

3.) I haven't looked too hard yet, but so far I have only seen Ampco in round rods...
Hate to take a 3.0" ++ round and machine it down to .015" thickness...

Any advice ?.. besides RUN!!!!! RUN Away! ?

Always looking for that next job... Have to look under a few rocks to find it..

The guy who used to make these parts... Sold the shop, Retired.
I don't think He wants to talk about them.. A bit of trauma. Off for the golf course therapy.

I'm very late to this conversation but wanted to speak on it anyway for those who come here in the future. First and foremost I do NOT work for AMPCO nor do I know anyone that works for them...now down to bidness!! The largest difference between the 2 metals is the price but there are distinct advantages to the AMPCO18 product. AMPCO18 has a max limit of .5% Nickel where C954 has a 1.5% max...This is crucial to wear when there is stainless steel in contact with the material, like a bushing for instance. Also, the AMPCO product utilizes a small grain manufacturing process that creates a more stable and strong product. Now this all being said, depending on the job your doing will make the decision for you if you can substitute C954 in place of AMPCO18. Many will say "AMPCO18 is superior so I want it instead!! Well that's a great thought but is it mechanically necessary? If you are creating a bushing that is in contact with a carbide rod then you can use either material with great success but if its a stainless steel rod and you don't want to make new bushings every few years then use the AMPCO. If you are building parts for medical equipment or food processing then AMPCO will be called and out you most certainly better use it, if you use the C954 in its place and there is a problem you will be liable so don't play games with that.Another way to look at it in its most simple form is like this, premium gasoline is better than regular, but would you spend all that extra money to put it into your lawnmower? The point is everything depends on the application.
Now the other part of the question, machinability. AMPCO I have found to machine a tick better than C954 because of its finer grain size but its no so different that its worth the extra money because the C954 machines quite well already. I hope this helps the next machinist or engineer out. I have years of experience with both of these materials and I spoke the truth...I just hope that i don't get sued for speaking it!!! peace all.
 








 
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