Recommendation for steel alloy for small shaft
Recommendation for steel alloy for small shaft
(OP)
We currently make a small shaft that is approx .375" diam x 4" long. There is such minimal stresses on the shaft that any steel would do the job. However, due to an oil seal riding on it, the shaft surface must be hardened to HRC 58-62. What we have used in the past is 8620 and carburized it. However, we need to outsource this part and finding that the extra grinding and treatments are getting expensive.
Is there by chance a magic bullet for this that would have high enough carbon to reach HRC 58 with just quench and temper? Ideally only harden to this level on the surface? I never like to use parts as quenched but with really no stress on the parts, it could be an option.
Is there by chance a magic bullet for this that would have high enough carbon to reach HRC 58 with just quench and temper? Ideally only harden to this level on the surface? I never like to use parts as quenched but with really no stress on the parts, it could be an option.





RE: Recommendation for steel alloy for small shaft
if none, how about starting with a drill or reamer blank?
http://www.vermontgage.com/Newprices/blanks/blanks...
If many, I'd be thinking about ion beam nitriding, flame hardening, or something similar.
Looks like standard "speedi sleeves" start around 1/2 inch shafts.
RE: Recommendation for steel alloy for small shaft
Could you use a hardchromed barstock and simply turn your part from it with no further treatments?
Just a couple of ideas.
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Recommendation for steel alloy for small shaft
We certainly are not getting our parts carburized and ground for 30C each though!
RE: Recommendation for steel alloy for small shaft
http://www.scotindustries.com/inventory.php
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
Another idea . . . While developing the aforementioned hydraulic pump, I tried 2 other methods experimentally before settling on the case hardened and ground 12L14. I had aluminum hard coat anodized with a teflon fill, and also used a ground stock shafting and had it electroless nickel plated, but I never tested either to a million cycles, I just ran out of time with the project, and always wondered how it would have worked out.
Good luck on the project!
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Recommendation for steel alloy for small shaft
But it does add steps.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: Recommendation for steel alloy for small shaft
There is concern of warpage in the part and we have always specified grind after heat treat. However, I just talked to a potential vendor that wants to grind BEFORE heat treat. I am a little nervous about that. If there is runout, there will be issues. 4140 for us has been extremely dimensionally stable in the size areas we work in. Love it. all diams and bores stay true. 8620 also seems a good alloy.
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
I might be curious about 1045 or 4150. Both have a little more carbon so guess could possible work?
I figure induction hardening to actually cost more than batch processing? Is there a major concern in hardness in the threads? The mating part is Aluminum and not under much torque. I could sure see though if we were torquing something down hard, there that could be an issue though!
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
Maui
www.EngineeringMetallurgy.com
RE: Recommendation for steel alloy for small shaft
If you were to use 1045 or 1050 the best induction hardening response would be with heats that have the manganese on the high end, or 0.80-0.90% Mn. Not always easy to find in a warehouse but it can be found with some extra effort.
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
I am looking hard at just batch treatment if 4150 with a low temper. The two questions I have are:
1. If we have them vacuum treated, will we still have a low micro finish if we grind "before" treating them?
2. The 3/8" shaft has a 1/4 male thread on the end. Could we get away with heat treatment of the threads? I DO realize they will become brittle but they are really only used to mate an aluminum hub that is only fitted one time and glue is applied to the threads. All load on it is radial.
RE: Recommendation for steel alloy for small shaft
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Recommendation for steel alloy for small shaft
threads have to stay male and really need machined when the shafts are made. Hard turning threads can suck and it is one more operation that will cost us hours. If it is done when still in the machine, it will take 15 sec/part.
RE: Recommendation for steel alloy for small shaft
Being so small diameter, can you just flame harden the area where the seal will be? 4150 in that size would probably harden just fine with a strong air blast for a quench. A 350F temper and a polish after flame hardening and you're done.
rp
RE: Recommendation for steel alloy for small shaft
RE: Recommendation for steel alloy for small shaft
We previously 8620 and carburized it. We are getting closer to that I guess...
If we flame harden, I will need to design a device to do that or I supposed outsource but that will not be cheap due to lack of batch processing. I might like the idea of drawing back the threaded part though. I was also curious about threading something on the threads during HT? However, with this much carbon, and the dims, I bet through harden is a given...