home made ring tool - drilling HSS?

[Shay Vings]

Thinking about making one of these from some spare HSS bar. Don't know much about metalwork so can you drill HSS with ordinary (TIN) twist drills or do I need a cobalt ?

Idea was to drill a nice neat hole of the desired dia. then do the rest on the edge of the grinding wheel. If it works, might even try making a beading tool same way. Or is this likely to be a waste of time.

 

[chipmunk]

Hi Shay,
You will not be able to drill HSS bar with either TIN or Cobalt drill bits I'm afraid.

I've had some success with Tungsten Carbide tile drills for drilling HSS but only up to 5mm holes in 3mm thick HSS (use plenty of drilling and tapping fluid). I've also drilled holes with small grinding wheels in a Dremel type multi-tool.

I hope this helps
Jon

 

[Shay Vings]

Thanks Jon. Pretty much as expected

BTW, I should have said captive ring tool ,rather than ring shaped cutting/hollowing tools

 

[chipmunk]

I just had a thought - dangerous I know :wink:

...but a snail countersink has a nice hole already formed albeit at an angle to the shaft. Can you use one of these as a starting point?

...just a thought
Jon