How do you do this?

[rjwz28]

I have a piece of metal rod 1" in diameter and 3" long with 2" of it being slightly over 3/4" dia. I need to fit this in some 3/4" holes nicely. It is a few thousands too large. How can I reduce the diameter a few thousands safely? I don't own a lathe, so that's out. I got a drill press but it is only a half inch one. If I could get it chucked in the press, I could run a file up and down while running the press on very slow speed. Any ideas how I can do this? Any other way? I would like to do it myself instead of sending it out.

Thanks in advance to everyone.
Rob

 

[PaulMarcel]

Could you epoxy a bit of wood dowel or metal rod to the end and chuck that part into the drill press?  Use a simple 5-minute epoxy.  To remove it, heat the rod.  You won't be able to put a lot of lateral force on it without supporting the other side.  You can support the other side by pressing on it with the shank of a large-ish drill bit.

Or you might just wrap the fat end with some sand paper and turn it by hand... you might be done before you'd start the other way (unless this rod is really hard).

 

[waho6o9]

drill a hole

tap a thread

screw in a bolt

chuck it up in a drill,  support the other end in a bearing
and file away slowly.  Be careful and good luck.

 

[AlexThePalex]

Put the rod in the freezer.

Metal shrinks when it gets colder. Might give you the few thousands you need. After it heats up again it will expand to its original size. If the part that needs to hold the rod can take that without breaking you can use this method.

Temperature treatment is a very much used connection method in the metal industry.

 

[rjwz28]

Thanks guys for the suggestions. 

Do you use different sandpaper for metal than wood?  I tried sanding by hand like a shoe shine with a strip of 100 grit Norton and didn't have much success.

Rob

 

[mastercabman]

Put the rod in the freezer.

Metal shrinks when it gets colder. Might give you the few thousands you need. After it heats up again it will expand to its original size. If the part that needs to hold the rod can take that without breaking you can use this method.

Temperature treatment is a very much used connection method in the metal industry.

yep, liquid nitrogen is also used for that purpose

 

[rjwz28]

Thanks but I need it to stay that size after reducing the diameter.  I don't want it to swell back to how it is now.  I need to be able to install and remove in the 3/4" holes.

Rob

 

[nclemmons]

Can you not chuck a dowel of maybe 1/2 or 5/8 inch in a drill with a slit in it to hold a piece of sand paper that is wrapped around the dowel and slightly enlarge the 3/4 hole to fit?  It sounded like it was in wood, which will be easier to enlarge than to make the steel smaller.

 

[flair woodworks]

Thanks guys for the suggestions. 

Do you use different sandpaper for metal than wood?  I tried sanding by hand like a shoe shine with a strip of 100 grit Norton and didn't have much success.

Rob

Yes, sandpaper for wood is different than sandpaper for metal.  Most abrasive papers for metal are dark in colour.  You can get wet/dry sandpaper in various grits from an automotive supply store.

 

[tbellemare]

You might try the emory cloth sold for plumbing (sweating copper). It makes quick work of copper though I didn't see where you mentioned what metal. Some metal is phenomenally tougher than others and copper is around the softest.

Tom

 

[Kodi Crescent]

Do the holes have to stay 3/4"?  Dumb question, but just asking.

 

[rmwarren]

I have a piece of metal rod 1" in diameter and 3" long with 2" of it being slightly over 3/4" dia. I need to fit this in some 3/4" holes nicely. It is a few thousands too large. How can I reduce the diameter a few thousands safely? I don't own a lathe, so that's out. I got a drill press but it is only a half inch one. If I could get it chucked in the press, I could run a file up and down while running the press on very slow speed. Any ideas how I can do this? Any other way? I would like to do it myself instead of sending it out.

Thanks in advance to everyone.
Rob

Google "cup chuck". This is basically a press fit chuck, in your example it would need to press fit over the 1" diameter and have a 1/2" shank. For low speed filing operations I suspect you could rig up something from hardware store items, perhaps a bolt and a PVC cap or something similar?

If you get too much deflection away from the pressure of the file you can just clamp a wooden backer against the back side of the portion you are filing to give extra support.

RMW