L.A.Van Royen Twist Drills and their Grinding

[Anonymous]

Posted by SillyOldDuffer on 10/01/2019 11:24:41:

Now I wonder where I got that from? I was confident it was a fact but now my reputation is on the line I can't find anything authoritative to support it.

It has cropped up every now and again for as long as I can remember. It might possibly have been true, to some extent, in the early days of HSS in the 1900s. But not now with more complex types of HSS with better heat treatment and understanding of the metallurgy.

Whatever the answer, I use carbon steel, HSS and carbide tooling as needed to suit the job and machine.

Andrew

[jacques maurelParticipant @jacquesmaurel42310]

You can read my articles in MEW about drill sharpening (the Van Royen is discribed as conical clearance). Issues N° 245, 246, 247. Issue 251 for small drills, and issue 256 for web spitting. I'm still working on the subject for further articles.

J Maurel

[IanTParticipant @iant]

I have quite a collection of 'carbon' tools and often use them in preference to HSS tooling when working brass – either on my smaller lathes or the hand shaper. They take a very good edge where fine cuts are required and many are forged to particular shapes that can be convenient on the shaper. They don't get hot enough to lose their hardness, which is more than sufficient for non-ferrous work.

As always these things depend on the context – horses for courses.. If I'm roughing out mild steel then obviously HSS holds up much better – but for shaving thous off brass, then a nicely honed carbon tool works very nicely and I've never had to worry about its "Rc" value!

I haven't got the math to understand most of the discussion here – but when those who 'do have' decide what's best – a simple "do it this way" would be quite good enough for me. All I want is something that drills to size and produces those lovely twin spirals of swarf. Sounds simple enough…

Regards,

IanT

[Author]

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