# What is it? Three point gage co.



## Charley Davidson (Dec 23, 2013)

Exactly what is this & how do you use it? I found it in the old Gershwin tool chest I got out of my Dad's shop.


----------



## OldMachinist (Dec 23, 2013)

Place the 3 contact areas on a metal pipe or electrical conduit and it shows what size it is. Looks like it also shows what size tap drill for the pipe sizes.

I haven't seen a 6" pipe tap in a long time.


----------



## DAN_IN_MN (Dec 23, 2013)

OldMachinist said:


> Place the 3 contact areas on a metal pipe or electrical conduit and it shows what size it is. Looks like it also shows what size tap drill for the pipe sizes.
> 
> I haven't seen a 6" pipe tap in a long time.
> 
> View attachment 66529



I can't even imagine the amount of torque required to cut threads with that thing!


----------



## Jim1942 (Dec 24, 2013)

Anybody know what this tool was designed for?  I bought a box of goodies at a sale that had some pieces of brass in it.  I recognized the tapered plugs and bushings, knowing they were used to plug leaking tubes in large refrigeration machines.  Also in the box was this knife looking thing with a lose fitting blade and a brass tapered assembly.  Thought at first glance, it must be some kind of deburring tool.  Other than that, I just don't know.  Would like to know for sure.  

Thanks,
Jim Dunn


----------



## Big Rack (Dec 24, 2013)

I believe that is a deburring tool for cut tubing or most likely EMT, flip it out slide the cone into the pipe to deburr the o.d. flip it in and the cone centers it for the i.d. Of course if you do much conduit work you can just your the cutter on your Klein's or buy one of their deburr tools that clamp onto your screwdriver shank.


----------



## hman (Dec 27, 2013)

Jim1942 said:


> Anybody know what this tool was designed for?  I bought a box of goodies at a sale that had some pieces of brass in it.  I recognized the tapered plugs and bushings, knowing they were used to plug leaking tubes in large refrigeration machines.  Also in the box was this knife looking thing with a lose fitting blade and a brass tapered assembly.  Thought at first glance, it must be some kind of deburring tool.  Other than that, I just don't know.  Would like to know for sure.
> 
> Thanks,
> Jim Dunn



It's a sharpening tool for cork borers.  

Until the advent of high-tech ground glass taper joints, chemists closed flasks and reaction vessels with real corks or rubber stoppers.  When a hole was needed in one, they used a cork borer.  Cork borers were brass tubes (sometimes nickel plated) with T handles on one end.  The other end was sharpened to a fine edge.  You twisted and pushed the borer to "drill" the required hole in the cork.  Cork borers came in sets, and you could use the next smaller borer to push the "plug" out of the borer you'd just used.  A solid pin was included for the smallest size.  

Also included was a device like yours.  You rotated the borer's ID on the brass cone while pressing the knife against the tube, to shave away the dulled area and form a new sharp edge.

Attached photo shows two sets of cork borers, plus the sharpener.



I doubt the tool has much of any value nowadays, but if you know a college chemistry student or teacher, they might be interested in seeing it.


----------



## Jim1942 (Jan 25, 2014)

Thanks John for the explanation of the cork borer.  Never heard of one of those before.  Always nice to learn something new.

Jim Dunn
Harrington, Delaware


----------



## jtwade (Feb 2, 2014)

Very interesting history lesson on the cork borer, might be almost useless information but I still like to see old tools and know their uses.


----------



## Nitrous (Apr 30, 2014)

jtwade said:


> Very interesting history lesson on the cork borer, might be almost useless information but I still like to see old tools and know their uses.



We still use rubber bungs in the lab. Rubber stoppers are still punched with those nesting corker bores. 

I've not needed to sharpen any of them (thank goodness for the tech dept) but they are still edge sharpened brass tubes. cole parmer still offers them for sale. 

http://www.coleparmer.ca/Product/St...t&mt=b&pdv=t&gclid=CL3I_8uFib4CFSISMwodFR8AtQ

Doug


----------

