Specs for 1/4" threaded drills

[thomaswimmer]

Hi,

does someone have a drawing/spec of the threaded part of the 1/4" threaded drills? I want to modify (read: have someone modify) a unibit to fit into an angle drill. The thread size, depth I can measure, the angle of the cone just at the end of the thread escapes me.


Thomas

 

[BrownTool]

1/4-28 Threaded Collet

Thomas,

Unless you really want to cut threads on a Unibit, there is an existing and very inexpensive tool that should take care of your needs. We sell (and I am sure the other tool suppliers sell as well) a $4.75 1/4" Threaded Collet that will allow you to adapt anything with a 1/4" shank (such as a Unibit) to 1/4-28 threads. You can see it on our website here:

http://www.browntool.com/Default.as...1&Level=a&SortField=ProductName,ProductNumber

We also stock all of the other common sizes, so that you can adapt regular non-threaded drill bits or accessories to the 1/4-28 threads of your angle drill.

Michael Brown
Brown Aviation Tool Supply Co.
Oklahoma City, OK
www.browntool.com
Michael "AT" BrownTool "DOT" com

 

[clevtool]

The collet Michael mentions is the best solution if you have a round shank Unibit. If you have the new hex style you may have to use a chuck which will also give you versatility in using other odd sized bits in the angle drill.

Brown sell them at: http://www.browntool.com/Default.as...oductName,ProductNumber&Level=a&ProductID=205

Or we do at:

[Text here that was promotional in nature was removed by the owner of the forums. Non advertisers cannot use the forums as a promotional tool (rule #5 at: http://www.vansairforce.net/rules.htm). Answering a specific, technical question that can be verified with a source is of course allowed - and encouraged!

]​

Make sure to feed VERY cautiously though, if you get the unibit stuck it will trash the gears in the angle drill faster than you can blink. Terry recommends a max drill size of 1/4" because of the induced torque.

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