Hardening surface treatments for small shaft
Hardening surface treatments for small shaft
(OP)
We have a small shaft that is approx .375diam x 3.5"L. It has an oil seal that rides on it and for that reason, it must have a very hard surface for wear resistance. It is a repair part for an OEM part. The OEM part tests approx HRC65 but with scratch methods, we believe it to be a bit harder but does not test well with the hardness tester.
Anyway, we previously specified machining of 8620 and carburizing, then grinding the OD to dimension.
We have lost of vendor for this work and cannot find anyone within our budget for them. For this reason, we are looking to determine if there are any other processes that can be considered to create a hard treatment? The structure of the part is not much concern. really any alloy steel will do as long as we achieve our surface hardness goals.
We also have a 1/4" thread at one and one of the things that is running cost up is having to machine, treat, grind, hard turn threads. We need to cut a step in there somewhere. A treatment that can be applied to a threaded shaft would be great but I should probably run some numbers before saying that due to brittle threads.
If there is a hardening treatment we could do in shop, that would be great but that might be reaching.
Anyway, we previously specified machining of 8620 and carburizing, then grinding the OD to dimension.
We have lost of vendor for this work and cannot find anyone within our budget for them. For this reason, we are looking to determine if there are any other processes that can be considered to create a hard treatment? The structure of the part is not much concern. really any alloy steel will do as long as we achieve our surface hardness goals.
We also have a 1/4" thread at one and one of the things that is running cost up is having to machine, treat, grind, hard turn threads. We need to cut a step in there somewhere. A treatment that can be applied to a threaded shaft would be great but I should probably run some numbers before saying that due to brittle threads.
If there is a hardening treatment we could do in shop, that would be great but that might be reaching.





RE: Hardening surface treatments for small shaft
-handleman, CSWP (The new, easy test)
RE: Hardening surface treatments for small shaft
RE: Hardening surface treatments for small shaft
I think what we were hoping for is a process that could work as a post machining hardening process. I think we could use a 4000 series alloy and draw back to an acceptable hardness before treatment BUT we have never tried this on threads and suspect they will be damaged in heat treat? We don't usually see much dimensional change with some other 4140 parts in heat treat do see surface changes.
Nitriding maybe?
RE: Hardening surface treatments for small shaft
RE: Hardening surface treatments for small shaft
You can mask-off threads and other features that do not need hardening. Most nitriding processes can be performed at 900-1100F, so you would see little distoriton or reduction in mechanical properties with a low-alloy steel provided the tempering temperature was above the nitriding temperature.
rp
RE: Hardening surface treatments for small shaft