Re: general question X

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi,

I have cut and filed pure tungsten.  Although, it is very hard and will
quickly dull a file or saw (hack saw with the expensive blades), it can be
done.  That is how I used to cut and size 1/8th inch tungsten rods for may
older rotary gaps.  A file can also make a notch and then you can snap the
rod to break it (safety glasses!).  I doubt you could make threads in
tungsten with a tap.  Probably and ECM machine but...  Sears sells titanium
drill bits that are for armor plate and such but drilling a hole in
tungsten would be an "adventure".  Pure tungsten 1/8 inch welding rods can
be found at any welding shop and they can order larger sizes if you have
enough money.  Some tungsten welding rod is slightly radioactive which I
avoid especially if you are going to be grinding it.  The pure kind is
common now so best to avoid the thorium kind IMHO.

I think tungsten carbide which is SUPER hard gets confused with the much
softer (but still very hard) pure tungsten.  I think only liquid cooled
diamond tools can touch it at the hobby level.  Marc has reported great
results with tungsten carbide in spark gaps and it is much more available
than big chunks of pure tungsten since it is commonly used for machine tool
cutters.

Cheers,

	Terry

At 10:07 PM 6/15/2001 -0400, you wrote:
>Tesla list wrote:
>
>> Original poster: "Wade B AndB Anderson by way of Terry Fritz 
>><twftesla-at-qwest-dot-net>" <nabedaw-at-juno-dot-com>
> 
>> hi guys,
> 
>> What type of material is tungsten? Hard or soft? is it drillable to tap?
>> or thread?
>
>	Some years back, i did some EMI studies on RF stabilized arc
>	welders.  The RF source is a spark gap.  Maintenance instructions,
>	from the manual, included:
>
>		Do Not Attempt to file the gap: the points are
>		tungsten, which is harder than the file.
>
>	best
>	dwp
>