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
