Hi Guys,
( I wrote this some days ago and I found today that I had not yet posted it, due to being called for dinner, oh the luxury of domestic staff
it's alright folks I am safe, she will never read this)They are certainly not a new idea and I would guess that the "patented" bit is only for the sharpening jig, as the basic idea would not be eligible for protection, due to it being public knowledge.
I have made both the Australian Style jig courtesy of Mr. Rick Kruger's drawings and the simple Vee style at 30 degrees. I find the simple jig to provide a better edge than the other one. I assume it is because of the direction of the striations, from the wheel, are in a better orientation for cutting, much like of a pair of scissors which only work properly with cross striations which grip the thing being cut. The Australian style jig does work marvellously for sharpening thread cutting tools.
There are many different ways of getting a good finish and a Tangential tool is merely one of them. Personally I love the Sumitomo T1200 Cermet tips but I am sure that many other manufacturers produce something nearly as good. The point about a Tangential tool is that it is an incredibly cheap thing to make and maintain. It is the most efficient way to use HSS, as it is only ever sharpened on the end, thus saving all the wastage caused by grinding on three sides.
I think there are many users who would question the "master of none" quip, but if that is a personal experience then fair enough. I would never force someone to use one or any other tool for that matter.
For a newbie who is afraid of sharpening HSS, these tools are a wonderful window on what HSS can do, even when sharpened with the simplest of grinding equipment and the minimum of skill. I know, as most of you folks will know too, that there is nothing to fear in grinding HSS but it does put people off and all those different angles can
appear a nightmare. I think most will agree that they are a better option for beginners than the wrong choice of carbide tip, as sold by some less reputable, or unaware, dealers. Even when bought as a readymade, the Ozzie tool does not compare too badly with what the the likes of Kennametal or Seco charge for their indexable tip toolholders, well at UK retail prices anyway.
Ned