For You Machinist Out There

[StarMetal]

Guys...say I have a metal shaft .444 in diameter and I want to put a sleeve on it to make it .500. The sleeve will be made from drill rod water cooled. I don't want to epoxy or silver solder it to the .444 shaft, I want to heat it and expand and slip it over the shaft. I don't want to heat it and have to really pound on it very hard. So what inside diameter would my .500 sleeve have to be? Thanks in advance.

Joe

[crazy mark]

I would try .442-.440 and freeze the shaft before you stuck the heated sleeve on. We used to sleeve horizontal steam powered water pumps this way. Had the sleeve .002-.004 oversize from the housing. Mark

[Buckshot]

....................Do as Crazy Mark suggested. Freeze one, heat the other. Hopefully you have a chest freezer that will run about -10. For heating you can use the oven cranked as high as it will go. How long are these parts, and how do you plan on pressing them together? Best to do it in one smooth stroke.

The larger the parts the larger the interferance before pressing. I'd stay around .002" max.

.................Buckshot

[OldBob]

StarMetal, what purpose does this sleeve serve? Reason I'm asking is you only have +/- .023 wall thickness and it may well not have the strength to maintain the press fit tension without stretching............. a bit of Locktite might not be a bad thing, a little heat will always let you remove it if necessary.

[350mag]

joe,
In the motorcycle shop when we made custom cycle sleeves we went with a .002 interference fit. That was a cast iron sleeve in an aluminum cylinder. Just FWIW.
Ken

[StarMetal]

Thanks for the help guys.

Joe

[redneckdan]

i'd make a it a tight fit, and use green 249 loctite, this model only needs to be heated to 300 degrees before it releases.

[HotGuns]

I use alot of interference fits at work.

We use the standard of .001 difference per inch of diameter.

There are different class if fits which require more or less intereference depending on what you are doing, the more severe the service the more fit you will require.

OldBob brings up a good point. Since you dont have much in the way of wall thickness, heating such a small piece may cause it to crack when it cools if you have too much fit,more so since its drill rod and it fairly brittle.

I wouldnt go with any more than .001 difference. That'll keep it there and you wouldnt be able to blow it off with dynamite...

[OldBob]

Exactly what I was thinking HotGuns, even though my math sucked a bit ! The rule of thumb for shrink fit steel parts is .001 per inch of dia. as you said. I have a lot of faith in the Loctite products, I have seen the green (can't remember #) stuff applied to a clean 3/8 bolt and nut and 1 hour later the bolt could be twisted in half before the joint broke. As long as this is an application where no great amount of heat is involved the Loctite should do the job easily and well.

[StarMetal]

I'm thinking of going the Green Loctite method. Now I know the Red and Blue are commonly available, but is the Green?

Joe

[OldBob]

Probably find the green stuff at an industrial supply house, welding supply house also might have it, we used to use it to seal porosity in MIG welds on oil tanks.

[redneckdan]

its loctite 249 bearing retainer.

[Calamity Jake]

Loctite 640 is the green stuff, we use it for rebuilding ford FWD trans. chain covers

[454PB]

If it were me, I'd make it oversize to prevent cracking, then turn it down after assembly.