# I drilled a hole...



## cathead (Apr 9, 2022)

Today I had a 4 inch diameter two foot long piece of shafting that needed to be cut in pieces and machined to 3.5 inch diameter.  Also needed was a
sizable hole through 8 inch long sections of shafts.  The drilling began with 1/2 inch, then one inch, then 1.25 inch diameter, then the biggest drill I have
which is 1 27/32 in diameter.  Some time ago I made a M4 to M5 adapter so I could use the huge M5 bit.  It all worked pretty well.
After that it will be boring.

When I was finished for the morning, the Monarch gearbox was actually slightly warm to the touch.  Well, enough for today as it is nice out and
the snow is melting once again since the latest dump.  









Next I need to clean up some swarf and get on with the next phase tomorrow maybe.


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## MrWhoopee (Apr 9, 2022)

Nice to have some real metal removal to do. You can tell you've done something. Looks like a coring drill.


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## cathead (Apr 9, 2022)

MrWhoopee said:


> Nice to have some real metal removal to do. You can tell you've done something. Looks like a coring drill.



It has a flat face and four flutes so needs at least a 1.25 inch starting hole.  It walks through metal like
butter.  I have had it for years and this is the first time I really needed to use it.


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## MrWhoopee (Apr 9, 2022)

cathead said:


> It has a flat face and four flutes so needs at least a 1.25 inch starting hole.  It walks through metal like
> butter.  I have had it for years and this is the first time I really needed to use it.


Yes, that's a coring drill. Designed for opening up cored holes in castings.









						.2188 TO 3.0 Inch Diameter Taper Shank Core Drill Bits High Speed Steel Series 522 4 Flute ID 869-
					





					www.carbideanddiamondtooling.com


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## Martin W (Apr 10, 2022)

The 4 flute drills are like a drill and reamer all in one. They make a pretty accurate hole size

Martin W


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