{"id":1752,"date":"2026-05-17T12:38:52","date_gmt":"2026-05-17T03:38:52","guid":{"rendered":"https:\/\/kirameki-translation.co.jp\/wordpress\/?p=1752"},"modified":"2026-05-17T12:38:52","modified_gmt":"2026-05-17T03:38:52","slug":"beware-of-%e3%83%95%e3%82%a1%e3%82%a4-%cf%86-%cf%86-and-%e3%82%a2%e3%83%bc%e3%83%ab-r-false-friends-from-iso-conforming-drawings","status":"publish","type":"post","link":"https:\/\/kirameki-translation.co.jp\/wordpress\/?p=1752","title":{"rendered":"Beware of \u30d5\u30a1\u30a4\/\u03c6\/\u03a6 and \u30a2\u30fc\u30eb\/R, False Friends from ISO-Conforming Drawings"},"content":{"rendered":"\n<p><strong>\u30d5\u30a1\u30a4\/\u03c6\/\u03a6<\/strong><\/p>\n\n\n\n<p>It appears that a technology problem in rendering the ISO drawing symbol for diameter, \u2205, has resulted in people thinking that the character is the Greek letter <em>phi<\/em> and this symbol is actually rendered variously and uniformly incorrectly in running Japanese text as \u03c6 (lower-case Greek letter <em>phi<\/em>), \u03a6 (upper-case Greek letter <em>phi)<\/em>, or \u30d5\u30a1\u30a4. All of these renderings are wrong. The correct character is \u2205, which is evoked in HTML by &amp;#8709; and in Unicode by U+2300.<\/p>\n\n\n\n<p>Although both \u30d5\u30a1\u30a4 and some of the above-noted symbols (mostly the incorrect ones) are used in running Japan text in place of the word diameter, this is simply wrong in English, even if you use the correct symbol, \u2205. Use the word <em>diameter<\/em> in running text and the abbreviation DIA in drawings in cases in which the ISO symbol \u2205 would not be understood (probably mostly in the US).<\/p>\n\n\n\n<p>None of the bogus symbols should appear in running English text.<\/p>\n\n\n\n<p>Examples:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u03c65\u306e\u68d2 {a 5-mm-diameter rod}<\/li>\n<\/ul>\n\n\n\n<p>In an ISO-conforming drawing of that rod, of course, the dimension could be indicated as \u22055.<\/p>\n\n\n\n<p><strong>\u30a2\u30fc\u30eb\/R<\/strong><\/p>\n\n\n\n<p>Here we have not a special character problem, but simply a misunderstanding the R (and its <em>katakana<\/em> rendering \u30a2\u30fc\u30eb) can and should be used to mean radius. R is the ISO drawing symbol for radius and has little proper use elsewhere. In a drawing, R10 means a radius of 10 mm, when we understand that a common dimensional unit in drawings is that dimensions, unless otherwise indicated, are in millimeters. Some Japanese authors will even use R as a faux unit. When asked, they might explain it as \u30df\u30ea\u76f4\u5f84. This is wrong and results by combining R with a drawing convention that, unless otherwise noted, dimensions are in millimeters.<\/p>\n\n\n\n<p>R should not be used in English to simply replace the word radius in running text.<\/p>\n\n\n\n<p>Examples:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30b3\u30fc\u30ca\u30fc\u306b\u30a2\u30fc\u30eb\u3092\u3064\u3051\u308b\u3002{Round off the corner(s).}<\/li>\n\n\n\n<li>R\u306f\u5c0f\u3055\u3059\u304e\u308b\u306e\u3067\u3001\u2026 {Because the radius is too small, \u2026}<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u30d5\u30a1\u30a4\/\u03c6\/\u03a6 It appears that a technology problem in rendering the ISO drawing symbol for diameter, \u2205, has resulted in people thinking that the character is the Greek letter phi and this symbol is actually rendered variously and uniformly incorrectly in running Japanese text as \u03c6 (lower-case Greek letter phi), \u03a6 (upper-case Greek letter phi), or &hellip; <a href=\"https:\/\/kirameki-translation.co.jp\/wordpress\/?p=1752\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Beware of \u30d5\u30a1\u30a4\/\u03c6\/\u03a6 and \u30a2\u30fc\u30eb\/R, False Friends from ISO-Conforming Drawings&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[246],"tags":[],"class_list":["post-1752","post","type-post","status-publish","format-standard","hentry","category-ja-en-translation-notes"],"_links":{"self":[{"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/1752","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1752"}],"version-history":[{"count":2,"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/1752\/revisions"}],"predecessor-version":[{"id":1754,"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/1752\/revisions\/1754"}],"wp:attachment":[{"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1752"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1752"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kirameki-translation.co.jp\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1752"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}