[Boatanchors] Help on drilling out knob setscrew

[Bob Hardie- W5UQ]

you know, that's a very good question... if it's harden steel, then how 
did it round out? 
A GOOD drill bit is needed... it will let go after drilling and some of 
the set screw threads WILL be left inside.  After knob removal, a "tap" 
the right size will remove the threads. 
Me thinks your drill bits were a bit dull....  :-)     Even good ones 
can become a bit dull and you need brand new ones...  left handed drill 
bits will work too if your drill is reversible. 
Gud Luk and gud nite...
Bob

Robert Nickels wrote:
> BOB wrote:
>   
>> If you can get a carbide drill of the right dia. and run it fast 
>> enough it will drill any hardened steel. You might have to find a 
>> machine tool supplier.
>>
>>     
> That was going to be my suggestion as well.  I had to drill out two 
> setscrews each on about a dozen knobs on a Hallicrafters HT-20 that 
> suffered corrosion, not a single one would budge!
>
> Have to admit I'm puzzled as to how the hex head got rounded out if the 
> screw is made of such tough hardened steel.   But I'm sure you can drill 
> it out with a carbide bit.
>
> 73, Bob W9RAN
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