Sorry guys, I did some digging around, and the original specs were in inches. Medically used wires have been around for about a century now, and it was either the British or the American wiring manufacturers who became a force in the industry, thus giving us these dubious standards.
Similar situation is with hypodermic needles--gauge (inch-based) for diameter and inches for length used exclusively in the US, and gauge may be used worldwide. Remek On Thu, Sep 17, 2009 at 12:42 AM, Pat Naughtin < [email protected]> wrote: > Dear Michael and Remek, > My first reaction was to suggest that the three sizes originally were: > > 350 µm (= 0.0137795 inch ~ 0.014 inch) > 450 µm (= 0.0177165 inch ~ 0.018 inch) > and 900 µm (= 0.0354331 inch ~ 0.035 inch) > > Cheers, > > Pat Naughtin > Author of the ebook, *Metrication Leaders Guide,* that you can obtain > from http://metricationmatters.com/MetricationLeadersGuideInfo.html > PO Box 305 Belmont 3216, > Geelong, Australia > Phone: 61 3 5241 2008 > > Metric system consultant, writer, and speaker, Pat Naughtin, has helped > thousands of people and hundreds of companies upgrade to the modern metric > system smoothly, quickly, and so economically that they now save thousands > each year when buying, processing, or selling for their businesses. Pat > provides services and resources for many different trades, crafts, and > professions for commercial, industrial and government metrication leaders in > Asia, Europe, and in the USA. Pat's clients include the Australian > Government, Google, NASA, NIST, and the metric associations of Canada, the > UK, and the USA. See http://www.metricationmatters.com > <http://www.metricationmatters.com/>for > more metrication information, contact Pat at > [email protected] or to get the free '*Metrication > matters*' newsletter go to: http://www.metricationmatters.com/newsletter to > subscribe. > > On 2009/09/17, at 14:15 , Michael Payne wrote: > > Looks suspiciously like 3,5 mm, 4,5 mm and 9 mm. The web site > http://www.heartsite.com/html/ptca.html only talks about a 2-3 mm tube, > what you saw could just be in inches because of the guy who designed the > package in the US. > > Mike Payne > > ----- Original Message ----- > *From:* Remek Kocz <[email protected]> > *To:* U.S. Metric Association <[email protected]> > *Sent:* Thursday, 17 September 2009 01:12 > *Subject:* [USMA:45822] Interventional surgery, wires, and metric. > > All of you are probably familiar with angioplasty, and that it entails > threading a thin catheter through one's blood vessel for the purpose of > expanding the blockage inside it. All catheters are deployed along > guidewires which range from 45 to 300 cm in length. The guidewires, oddly > enough, have their diameters measured in inches. It seems to be a worldwide > standard, since the packaging is multilingual (not just NAFTA), and only > inches are mentioned for diameter, with 3 standard dimensions being 0.014, > 0.018, 0.035" > > Is anyone familiar with the origins of this? Is this the US wiring > industry forcing another inch-based standard on the world? Or some sort of > a holdover from 19th century? > > Remek > > >
