The kind of sparks given off when grinding will give you a hint at to what kind of steel your dealing with. Here's one site I found describing the different sparks. http://www.capeforge.com/Spark%20testing.html I've always heard that a sharp tool is a safe tool. There's no better feeling then pushing a chisel that you've sharpened through some wood and it slides like butter. Les Date: Sat, 09 Oct 2010 09:10:22 -0700 From: <johnparham at piano88.com> To: pianotech at ptg.org Subject: Re: [pianotech] Of Chisels Message-ID: <20101009091022.f1fd8b108a58a93f763c4cd7f53850a9.fe2cdc6be6.wbe at email03.secureserver.net> Content-Type: text/plain; charset="utf-8" In following this post on sharpening chisels, I ran across two interesting facts on sharpening kitchen knives that may apply here as well: 1. If you see sparks during the sharpening process, too much heat is building up. The result is you loose the temper on the blade. 2. The evolution from cast iron (hard, but brittle and prone to rust), to carbon steel (harder, but still brittle and still prone to rust), to stainless steel (hard, resilient and much more rust-resistant) has led to the development of a new kind of steel called ultra-high carbon steel. This steel contains a much higher concentration of carbon, making it even more resilient. More resilience means the very sharp metal edges are less prone to breaking off. These edges tend to last 5-10 times longer than traditional stainless steel edges, so the blade stays sharper longer. I wonder if some of these Japanese tools use this kind of metal? -John Parham Hickory, NC -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20101010/a9af1261/attachment.htm>
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