# Drilling a hole through a socket



## Pcmaker (Dec 22, 2018)

I want to put a set screw on a 1/2" socket. I didn't even use an edge finder, I just eyed the center of the socket. Then I used a #3 center drill to start the hole, then I used a 1/4" cobalt drill bit to drill through on my PM-25mv. I couldn't drill the hole. I switched to a new 1/4" cobalt drill bit, and still can't do it, even with plenty of cutting fluid and tried different RPMs. I locked all the axis locks, still can't do it. 

Did I jump to using a 1/4" bit too soon?


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## P. Waller (Dec 22, 2018)

No, never drill a pilot hole if not needed.
For such a small hole just spot then drill to size, your problem is almost certainly feed rate.
Power feed the drill as fast as possible, if it is just rubbing on the material you will not get what you want and use a good deal of drill bits doing so.

The worst that can happen is a broken $20.00 drill bit.


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## JimDawson (Dec 22, 2018)

I think you are turning way too fast.  Slow the spindle speed down to minimum, sockets are pretty hard, and many have a chrome finish which is very hard.  Once the drill tip is through the chrome, then it should drill OK.  If needed, grind the chrome off of the area that you are going to drill.


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## benmychree (Dec 22, 2018)

This discussion neglects one important issue; even if you are able to drill it, how do you plan to tap it? As hard as sockets are, the chances of tapping a hole in it are nil.


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## Tozguy (Dec 22, 2018)

How far did you get with the no. 3 center drill ? if the center drill worked then so should a cobalt drill.
A 60 deg. hole is not the right angle for a 118 deg drill bit. What did the drill tip look like after you tried everything?
Good advice above, hope it works out for you.


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## Pcmaker (Dec 22, 2018)

Had zero issues with the center drill, it was also cobalt.


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## jdedmon91 (Dec 22, 2018)

benmychree said:


> This discussion neglects one important issue; even if you are able to drill it, how do you plan to tap it? As hard as sockets are, the chances of tapping a hole in it are nil.



I’ve drilled and tapped sockets. In full disclosure it was 1/4 x 20. I used a center drill, then I drilled the tap hole for 50% thread depth then tapped the hole. Because of the of the hardness of a socket you do have to be careful. 


Sent from my iPhone using Tapatalk


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## timmeh (Dec 22, 2018)

Slow spindle down, min. speed. Heavy on the feed, good dollop of oil, CRC/wd40 or the like up front.
I drilled with HSS. So tapping should be fine, a little extra clearance on tapping hole size, start the tap while still set up in drill/mill. Not Under Power!!!


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## mmcmdl (Dec 22, 2018)

Sounds like you're making hex bit drivers ?


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## markba633csi (Dec 22, 2018)

You might try a carbide tipped bit of the type used to drill holes in porcelain and tile- use a slow speed. Bosch makes some good ones.
mark


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## rgray (Dec 23, 2018)

Impact socket to start with if possible. No hard chrome and easy to drill and tap. 
Impact sockets are tough....Not hard... there is a big difference.


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