shrink fit metal tubing

[bert-nc]

with very limited metal working equipment I have decided to shrink fit a plug (1 3/4 round 1018 bar) into a  dom metal tube. Do I need to heat the tube and cool the plug, or will heating the tube be sufficient? Trying to make a golf ball mortar.

all comments and suggestions appreciated

bert-nc

[Cat Whisperer]

Bert -

WELCOME to the board!

What caliber is it now?

[cannonmn]

You lost me on why it needs a plug?

[Double D]

High Bert-NC  and welcome.

You might give us a few more details about what you are making  an some dimensions of the material you are working with.

[KABAR2]

You lost me on why it needs a plug?

I think he is using Drawn over a mandrel tubing and wants to breech it by shrinking a plug in place,

he should look at our stickies for wall thickness before considering this, also he did not mention whether

or not it would have a chamber in the breeching, or any sort of welding....... need lots more info.......

[bert-nc]

working on more details---

will post a better description monday afternoon

bert-nc

thanks for the welcome

have been reading for a while as a guest

[GGaskill]

Steel expands about 6 millionths of an inch per inch thickness per degree Fahrenheit.  So whether you need to heat one and shrink the other depends on the dimensions of the two parts and how hot and cold you can get things.

[bert-nc]

Steel expands about 6 millionths of an inch per inch thickness per degree Fahrenheit.  So whether you need to heat one and shrink the other depends on the dimensions of the two parts and how hot and cold you can get things.

thanks,
that was what I needed to know

bert-nc

[bert-nc]

 

some details about the  mortar that I am building.
3 inch outside diameter barrel, 1.75 inch bore, 7 inches long, .625 inch wall
powder chamber is 1 inch diameter x 1.75 inch deep
total wall around powder chamber is 1 inch thick
all but ready to place the powder chamber into the barrel by shrink fittiing.
I believe I will heat the barrel to do this.
Tried to include a rough drawing but for some reason it did not show up.
welcome all questions or concerns

bert-nc

[GGaskill]

You don't say whether the inside of the tubing will be machined to fit the plug.  It should be unless the hole is accurately circular within a couple of thousandths.  The thick tube will not distort enough to fill in voids due to non-circularity of the tube.