To add further confusion, Wikipedia and sizes.com report that some countries, like Sweden, use the deprecated kilogram-force. So the same oak which is "basic" hardwood flooring here could be rated 6.0 kN, 610 kgf, or 1350 lbf. "What number would you like? We'll just omit the units, make up new units, and deliver whatever results please you."
--- On Tue, 9/15/09, Pat Naughtin <[email protected]> wrote: From: Pat Naughtin <[email protected]> Subject: [USMA:45814] Re: Semi-metric wood hardness measurement To: "U.S. Metric Association" <[email protected]> Date: Tuesday, September 15, 2009, 2:27 AM Dear Jim and John, This might be useful to develop comparative figures using kilonewtons per 100 square millimetres (using a ball diameter of 11.28 mm). http://www.borthwick.com.au/species/hardness-rating The reference to 0.444 inches in this context is simply superfluous information that is quite unnecessary and even confusing. You might also find the sections labelled timber species and grades of timber interesting. 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 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 2009/09/15, at 02:38 , John M. Steele wrote: The government loves those mixed units. Automobile emission limits are grams per mile. --- On Mon, 9/14/09, James R. Frysinger <[email protected]> wrote: From: James R. Frysinger <[email protected]> Subject: [USMA:45811] Semi-metric wood hardness measurement To: "U.S. Metric Association" <[email protected]> Date: Monday, September 14, 2009, 11:14 AM What was not specified there was the unit of force that is used to come up with the numerical values. This is of course not the first time I've seen folks spout numbers without units! Further research led to a USDA research note: Janka Hardness Using Nonstandard Specimens http://www.fpl.fs.fed.us/documnts/fplrn/fpl_rn303.pdf This indicates that the units cited in the first reference are likely in pounds force (lbf), equivalent to 4.448 N to 4 places. The research note tabulates results in "lbf/cm2", which really yanks my tiny brain around! Jim -- James R. Frysinger 632 Stony Point Mountain Road Doyle, TN 38559-3030 (C) 931.212.0267 (H) 931.657.3107 (F) 931.657.3108
