Stainless Plain Bearings

[aboard_epsilon]

I'm making plain bearings
for the swing-arms of my boat trailer.
why stainless......because the thing will be submerged in salt water.
I've made the bearings .......out of 400 grade stainless..that's all I can tell you ......it's slightly magnetic and was the hardest thing I've ever drilled.
UNIDENTIFIED SCRAP YARD STUFF.
If titanium is magnetic then it could well be titananium ..I struggled with cobalt drills.
Now the pins that go into these bearings I've not made yet....they will be 1 inch diameter
1.do I make them out of stainless as well
2. do you think I should make them out of a softer metal....there would be less strengh then..(trailer will carry about 1.5 tons.
I ask because ..there must be something in this softer metal against harder metal as bearings because they've been doing it for years in car engines.
or does this not count here because bearings pins will only be turning thru 20 degrees...and want be doing it very fast.
bear in mind that I dont have much money to go out and buy some smart stainless roller bearings
All the best..mark

[JIMofalltrades031]

stainless pin and put in zerk fitting for grease. And grease religously after every dunking. I am thinking you may have work hardening trouble from this. Good luck jim

[WJHartson]

Stainless on stainless has a tendency to gall quickly. Think you would do better with something other that stainless in both places. Have you considered a dense plastic or bronze bearing and a stainless pin.

Joe

[wierdscience]

Joe is right,stainless on stainless,bad idea,steel on stainless still bad idea.It will probably make two swings and never swing again.
I would bore out the hole,or reduce the pin diameter and work in a plastic or bronze sleeve.

[This message has been edited by wierdscience (edited 01-09-2005).]

[zl1byz]

Yep Joe & wierdscience are onto it. Sorry Mark, hope you had fun making those stainless bushes. http://bbs.homeshopmachinist.net//smile.gif Does sound like they work hardened on you. http://bbs.homeshopmachinist.net//frown.gif Don't know what the others think but I would tend to favour plastic bushes.

JOhn.

[Mcruff]

400 series stainlesss will rust in salt water.
Any stainless that has magnetic properties is usually a toolsteel type or hardenable stainless and will rust. It will take alittle while but it will rust in a few months. We used to use it in food procesing parts where we needed its strength.