Creating curved holes


Can anyone tell me how to bore a curved hole into a solid piece. I
want to put a curved bar through a bangle (a bit like a belly bar
piercing.) Any suggestions?

Thanks Steven.


And I usually try really hard to drill straight holes :slight_smile:

A couple of thoughts…

  1. Split the piece and carve matching curved 1/2 round grooves,

  2. Drill two straight holes on an angle which intersect. Ball burr
    the corner intersection. It won’t be a round hole inside but that’s

  3. Make the piece hollow and solder in a curved tube.

Demand Designs

Thanks for the ideas Jeff, i really want the piece to be solid so
drilling from both sides seems to be the best option. Or maybe i
should forget jewellery and look into manufacturing curved drill bits

Regards Steven

Or maybe i should forget jewellery and look into manufacturing
curved drill bits etc. 

If you do so, don’t forget to include sky hooks and left-handed
wrenches in your catalog.


If you can cast the piece, you could do this pretty easily. Use a
curved tube of polystyrene, uncooked macaroni, or whatever is the
correct thickness for the bar you want to insert. Form the wax around
that core and then remove the core and cast.

As a hint, if you spray the polystyrene very lightly with WD-40,
Pam, olive oil, or some such, it will release beautifully from the
wax. The macaroni should do likewise.

Alternatively, if you have a polystyrene tube/macaroni that the bar
you want would fit into, go ahead and form it the same way (without
the lubricant) but cut off the tube flush with the surface of the
wax. This will leave you with a beautifully formed and supported tube
all the way through.

One additional consideration will be the curved tube and burnout.
Mix a small amount of investment and fill the curved tube with it
prior to investing the rest of the flask. That way, you won’t end up
with bubbles or an incomplete tube. You can fill it (depending on its
dimensions) by using a syringe, or using a toothpick or similar
object to push the investment into the tube.

Hope this helps!

Karen Goeller
No Limitations Designs
Hand-made, one-of-a-kind jewelry

Or maybe i should forget jewellery and look into manufacturing
curved drill bits etc. 

Drilling curved holes has been done for at least 60 years; spark
machining will drill holes of any shape and size, curved or not in
hardened steel. I have seen the shape of half a pair scissors drilled
into steel stamping dies

the full depth of one half of the scissors, and a curved 60* hole in
a block of similar quality steel. This was done at the Cutlery
Research Dept of the British Iron and Steel Research Association in
Sheffield, UK. One problem: this was a research prototype made in the
workshops, and if they are now on the market, which is likely, they
would be costly.

Cheers for now,
JohnB of NZ