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From: Mike Lee - Team Banana Racing[SMTP:mikel@ichips.intel.com]
Sent: Friday, January 10, 1997 1:39 PM
To: shop-talk@autox.team.net
Subject: thickness of different gauge sheetmetal.
A very basic question I'm sure, but they say the dumbest question
is the one that isn't asked.....
I always thought that was the one asked often, because the answer wasn't
listened to . . .
What is the correlation between the thickness of a piece of sheetmetal
and it's gauge? I know the gauge is used as a measurement, and is
inverse to the thickness (i.e the higher the gauge number, the thinner
it is), but what is the actual correlation? Or, what is the formula
for determining that #16 is .xxx" thick, and #22 is .xxx" thick? Or
is there a table that I must memorize?
United States Standard Gage (as described in Pender/McIlwain's EE Handbook,
1936 edition) is a weight gage; they spell it without the u. It is based
on weight per square foot. A formula doesn't hold in that it includes gage
numbers from 0000000 to 0 to 1 to 44. So . . . you've got to memorize a
table. There will be a quiz later in the day.
<switching to non-proportional font, and I recommend you do the same>
gauge ounces/ thickness,
sq. foot inches
0000000 320 0.490
000000 300 0.460
skipping a bunch
4 150 .2298
5 140 .2145
and some more
10 90 .1379
11 80 .1225
12 70 .1072
13 60 .0919
14 50 .0766
15 45 .0689
16 40 .0613
17 36 .0551
18 32 .0490
19 28 .0429
20 24 .0368
21 22 .0337
22 20 .0306
23 18 .0276
24 16 .0245
skipping some more
43 3 1/8 .0048
44 3 .0046
and be sure to add 2.5 ounces per square for galvanized stock.
Not as straightforward as wire gauges. There each successive gauge is the
39th root of 92 bigger than the previous. (but 3 gauge sizes doubles the
amount of wire, give or take)
Mark Miller
possessor of some very old but easy to understand reference books.
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