{"id":5688,"date":"2019-03-06T22:05:00","date_gmt":"2019-03-07T03:05:00","guid":{"rendered":"http:\/\/www.rpwoodwork.com\/blog\/?p=5688"},"modified":"2019-03-06T22:05:00","modified_gmt":"2019-03-07T03:05:00","slug":"more-on-sharpness-tests","status":"publish","type":"post","link":"https:\/\/www.rpwoodwork.com\/blog\/2019\/03\/06\/more-on-sharpness-tests\/","title":{"rendered":"More on sharpness tests"},"content":{"rendered":"\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"570\" height=\"355\" src=\"https:\/\/www.rpwoodwork.com\/blog\/wp-content\/uploads\/2019\/03\/IMG_5098_edited-2.jpg\" alt=\"sharpening plane blades\" class=\"wp-image-5691\" srcset=\"https:\/\/www.rpwoodwork.com\/blog\/wp-content\/uploads\/2019\/03\/IMG_5098_edited-2.jpg 570w, https:\/\/www.rpwoodwork.com\/blog\/wp-content\/uploads\/2019\/03\/IMG_5098_edited-2-150x93.jpg 150w\" sizes=\"auto, (max-width: 570px) 100vw, 570px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Sharpening is so much at the core of hand tool woodworking, and so here are a few thoughts that build on the <a href=\"https:\/\/www.rpwoodwork.com\/blog\/2019\/02\/24\/how-do-you-know-its-sharp\/\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"previous post (opens in a new tab)\">previous post<\/a> on sharpening tests.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>1.<\/strong> Can we close the loop and say that the proxy tests are actually <strong>validated<\/strong> by the tool&#8217;s performance? Based on experience, yes, regarding sharpness, edges perform as the tests predict. The tests are worthwhile.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>2.<\/strong> <strong>Edge endurance<\/strong>, however, is another matter. There you are relying on the <strong>&#8220;design&#8221;<\/strong> of the edge and the reliability of your sharpening <strong>process<\/strong>. The only &#8220;test&#8221; is over time \u2013 seeing how long the edge lasts. For good results, you must match the edge geometry to the steel and the task.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>For example,<\/strong> A-2 is a good choice of steel for a jack plane blade but if the bevel angle is too narrow, such as would be good for O-1 steel, the edge will be prone to premature chip-out.\u00a0<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>As another example,<\/strong> a plane blade with a wide bevel angle (e.g. 43\u00b0), though correctly employed in a bevel-up plane to create a high attack angle to reduce tearout, will necessarily have a shorter useful working life than narrower edges.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>3.<\/strong> <strong>Squareness<\/strong> or, as appropriate, the correct skew angle, is, of course, easy to test. By the way, I find that a chisel edge that is just a bit out of square is not a big deal, as is sometimes supposed. There&#8217;s also a bit of squareness tolerance in most plane blades.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>4.<\/strong> For many woodworkers, the most vexing matter of edge geometry is plane blade <strong>camber<\/strong>. For choosing, producing, and assessing camber, I invite readers to visit <a rel=\"noreferrer noopener\" aria-label=\"this series of five posts (opens in a new tab)\" href=\"https:\/\/www.rpwoodwork.com\/blog\/tag\/plane-iron-camber\/\" target=\"_blank\">this series of five posts<\/a>, which is about as in-depth a treatment of the subject as I think you will find anywhere.\u00a0<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Stay sharp, amigos.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Sharpening is so much at the core of hand tool woodworking, and so here are a few thoughts that build on the previous post on sharpening tests. 1. Can we close the loop and say that the proxy tests are actually validated by the tool&#8217;s performance? Based on experience, yes, regarding sharpness, edges perform as [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-5688","post","type-post","status-publish","format-standard","hentry","category-techniques"],"_links":{"self":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/5688","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/comments?post=5688"}],"version-history":[{"count":3,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/5688\/revisions"}],"predecessor-version":[{"id":5694,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/5688\/revisions\/5694"}],"wp:attachment":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/media?parent=5688"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/categories?post=5688"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/tags?post=5688"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}