{"id":429,"date":"2009-07-11T01:04:36","date_gmt":"2009-07-11T06:04:36","guid":{"rendered":"http:\/\/www.rpwoodwork.com\/blog\/?p=429"},"modified":"2009-07-11T15:53:27","modified_gmt":"2009-07-11T20:53:27","slug":"end-mills-vs-router-bits-for-mortising","status":"publish","type":"post","link":"https:\/\/www.rpwoodwork.com\/blog\/2009\/07\/11\/end-mills-vs-router-bits-for-mortising\/","title":{"rendered":"End mills vs. router bits for mortising"},"content":{"rendered":"

\"\"<\/a><\/p>\n

And the winners are . . . end mills!<\/strong> Here\u2019s why.<\/p>\n

I do most of my mortising<\/a> with my trusty Elu 3338 plunge router<\/strong>, currently available as the DeWalt 625, in conjunction with various jigs, most involving a template guide riding in a slot. In the past, I used solid carbide upcut spiral router bits<\/strong> with generally good results, though I often encountered two problems.<\/p>\n

First, 1\/4″ and 3\/8″ spiral bits are usually sold with cutting lengths of 1″ and 1 1\/4″, respectively. I often want to make mortises deeper than that. Second, 1\/4″ and 5\/16″ diameter bits, especially some rare, long-length, HSS versions, will sometimes vibrate<\/strong> in the cut and produce steps on the mortise walls. Even a 3\/8″ bit\u00a0may be made with a surprisingly thin web at the core of the spiral which can cause the bit to flutter when cutting dense woods.<\/p>\n

I like standard, four-flute, center-cutting, single end mills in uncoated solid carbide with a plain shank and a 30-degree helix<\/strong>. These are available in longer overall lengths with longer cutting lengths than router bits, thus allowing deeper mortising. I find the cutting action of these four-flute end mills has less vibration and is smoother and more balanced than that of router bits. This results in cleaner mortises. Furthermore, these end mills are generally less expensive than comparable router bits.<\/p>\n

The photo at top shows, from left to right, 1\/4″ and 3\/8″ upcut, solid carbide router bits, and 1\/4″ and 3\/8″ end mills. The 3\/8″ end mill is 4″ long with a cutting length of 1 3\/4″. The router bits tend to strain in the cut whereas the end mills purr like a sports car<\/strong>. The mortise pictured below is 3\/8″ wide, 2 3\/8″ long, 1 1\/2″ deep and was cut in bubinga, a dense wood, with the bit at the right in the top photo. The walls are very clean and true.<\/p>\n

\"\"<\/p>\n

The disadvantage<\/strong> of an end mill is that the cutting diameter equals the shank diameter. Therefore, I usually mortise with a 1\/4″ or 3\/8″ end mill using a router collet of the same size for each. A 5\/16″ end mill can be used with a shank adapter though I prefer to avoid these adapters. When mortising with end mills, just as with router bits, it is good practice to cut the mortise in small depth increments, always listening to and feeling the feedback from the machine and adjusting your technique accordingly.<\/p>\n

Sources for end mills are industrial supply houses<\/strong> such as MSC<\/a>, Enco<\/a>, McMaster-Carr<\/a>, and Grizzly<\/a>. It will take a while to go through their catalog algorithms or directly study their catalog pages but these are good ways to learn about this type of tooling. The upgrade has been worth it <\/a>for me.<\/p>\n","protected":false},"excerpt":{"rendered":"

And the winners are . . . end mills! Here\u2019s why. I do most of my mortising with my trusty Elu 3338 plunge router, currently available as the DeWalt 625, in conjunction with various jigs, most involving a template guide riding in a slot. In the past, I used solid carbide upcut spiral router bits […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-429","post","type-post","status-publish","format-standard","hentry","category-tools-and-shop"],"_links":{"self":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/429","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=429"}],"version-history":[{"count":6,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/429\/revisions"}],"predecessor-version":[{"id":436,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/429\/revisions\/436"}],"wp:attachment":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/media?parent=429"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/categories?post=429"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/tags?post=429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}