Thread: Stainless Steel or 4140

Hi OH,

Might be a good idea to contact a stainless steel/steel supplier who would have all the info. Have you had any problems with electrolysis previously?.

MH

http://www.matweb.com/ will allow you to find out the material properties of a huge range of materials. You will need to specify the type of stainless.

The Rockwell B hardness of most SS ranges from about 70 to 90) average is about 85 . For annealed 4140 the Rockwell B is 92. The thing is you can heat treat the 4140 and get it much harder if you want to.

Cehers

Originally Posted by Oldhack

I need to make some sleeves that press fit onto aluminium spacers, the sleeves give a hard wearing surface to the spacers where a oil seal runs.
I have made these in the past out of 4140, but it has been suggested I use Stainless Steel.
But I think 4140 has a higher hardness, and there for better wear properties.

any thoughts

What about just getting speedi sleeves in the correct dimension and using that to give you oil seal surface. They are designed for bearing and seal surfaces and have the required hardness. They are very thin as well and just press on. Bearing shops sell the stuff.

thanx for the feedback the spacers are rear axle spacers on an enduro bike.
the grit etc gets under the lip of the seal and gouges the aluminium, hence the need for a wear ring. they are approx 30mm diameter.

will check out the Speedi Sleeves, but I have 4140 and 316 S/S so its no big deal to M/c them

I'm thinking the S/S was suggested for corosion resistance

4140 is usually considered a 'stainless steel' & is what a lot of knife makers use for their blades.

There shouln't be any electrolisis issues as the bearing is lubricated.

I have done plenty of bearings with 4145 with a dissimilar contact material and had no issues with electrolisis when well lubricated.

Oldhack

Given your application, I think the harder the surface the better. 4140 in its annealed state is not hard enough to withstand an abrasive grit like you describe.

Mating aluminium and stainless together in an application that can get wet is probably not a good idea. I have seen recent evidence of the result of doing this on a machine we imported at work which has a s/s rhs frame with aluminium panels. Where the two were in contact, there was a notable white powdery build up on the aluminium. And this didn't get wet, just exposed to sea air on the boat trip out here.

If you are going to use s/s, 316 does work harden so it would probably be a better choice for a hard surface than annealed 4140.

Another option would be to use a bit of Bisalloy 360 (about 40 Rc) or Bisalloy 500 (about 50 Rc). This is usually only available as plate and is used for things like excavator buckets. This stuff is very wear resistant but also much harder to machine.

If you have any heavy engineering machine shops close by, they might have a bit of scrap they could sell you.

Last but not least is aluminium bronze or phosphor bronze. Both of these bronzes are very hard and wear resistant and also won't rust. Thes materials are also typically used in bushes on earth moving equipment.

Hope this helps

regards
John

Originally Posted by JTonks

Mating aluminium and stainless together in an application that can get wet is probably not a good idea. I have seen recent evidence of the result of doing this on a machine we imported at work which has a s/s rhs frame with aluminium panels. Where the two were in contact, there was a notable white powdery build up on the aluminium. And this didn't get wet, just exposed to sea air on the boat trip out here.
regards
John

Not necessarily. See http://www.woodworkforums.ubeaut.com...ad.php?t=48057 post #7. It sounds like what you observed didn't have enough contrast in the areas of the two metals.

Joe

thanx for the excellent feedback.

I have decided to make the spacers out of solid 316 for a number of reasons

1 its easier than machining the wear ring abd getting the "fit"

2 the extra wieght will be next to bugger all in the overall scheme of things.