[garagefela]

Do you think the reducer would hold bettter/stonger if I cut some shallow wide threads on the piece before freezing and dropping into the tube? This way when it expands back to normal the cuts/threads would grip the inside of the tube.

I forgot on the last post to thank everyone for the advice!

Just consider that removing any metal in the interference area will actually reduce the amount of metal to metal contact.

Just a good machined finish at the correct interference is the go. No polishing if possible.

[martinw]

Plumbers use this stuff to freeze water pipes. It might be a useful tool, but I am not giving any promises. It is certainly a handy dispensing system.

http://www.screwfix.com/prods/13369/...OCFFQ?ts=19065

Best wishes,

Martin

[Cruiser]

Fishing Rod, Think about it ! a machined tube is threaded by the nature of the cutting process so cutting @.006" feed would be a 166.6666 pitch thread.

[Geof]

But if the tip of your tool is 0.007" wide there is no thread.

[mc-motorsports]

Ray has it right, .001" tops for the press/shrink fit. I've never seen press/shrink fit parts made on a lathe, they are usually ground for precision taper (no taper) and tolerance. And you shouldn't need to cool the ID part, heating the ID part is sufficient. Use a heat gun, or a propane torch (no oxy) at the lowest flame setting you can sustain, and heat it up until your finger sizzles when you just bump it, around 180*F if your tolerancing/interference is correct.

I used to shrink fit bearings daily. And I would inspect, or machine, or chrome and remachine the parts to tolerance before fitting.