#2 Pencils
October 2, 2004 7:40 PM   Subscribe

What's so dad-blasted special about #2 pencils? Surely a test-scanning system could be devised that just looked for the blackened marks?
posted by kenko to Society & Culture (8 answers total)
Because the marks #2 pencils produce are dark enough to be read by a machine without being prone to lead breakage and smearing. In other words, they're optimal for both tester and testee. Uncle Cecil's crew has the last word.
posted by Danelope at 8:02 PM on October 2, 2004

There are actually #1 through #6 pencils readily available, at your local art supply store. (Higher numbers, which pretty much are only used by architects, might be harder to find)

I needed a whole set for life drawing classes. #2 is basically the standard because it's a good combination of lead thickness and heavyness of the lead. Harder lead would risk imprinting on the paper (I once tore a newsprint pad with a #4 or #5 sharpened pencil)

On the other end, a horrible "there is no tooth fairy" moment for the ScanTron side of the issue- it is just the optical scanning of darkness levels. In most modern machines, basically any dark mark can apply. Pencils are preferred because unlike ink there's less of a risk of the mark bleeding to the other side of the paper and screwing things up, but as long as it's dark, the machine will read it.
posted by XQUZYPHYR at 9:43 PM on October 2, 2004

The 'H' stands for hardness, the 'B' stands for blackness, and HB is for hard and black pencils. The hardest is a 9H, followed by 8H, 7H, 6H, 5H, 4H, 3H, 2H, and H. F is the middle of the hardness scale; then comes HB, B, 2B, 3B, 4B, 5B, 6B, 7B, 8B, and 9B, which is the softest. Another grading method uses numbers; the equivalents would be #1=B, #2=HB, #2-1/2=F, #3=H, and #4=2H. The most commonly used writing pencil is the #2 (HB grade), which is fairly soft, contains more graphite, and leaves a dark mark.

Thus an HB is an ideal lead, a bit hard and dark.
posted by riffola at 10:07 PM on October 2, 2004

Sorry, I forgot to link the site where I copied this from... The Pencil Hardness Test
posted by riffola at 10:08 PM on October 2, 2004

6B's rock for drawing, though. You just can't get real "black" out of a #2 -- no matter how hard you press, the best you can get is grey. Bleh.
posted by Civil_Disobedient at 3:09 AM on October 3, 2004

You probably could use a pen on a standardized test if you wanted -- but heaven help you if you make a mistake on your SAT or LSAT.
posted by herc at 10:07 AM on October 3, 2004

Pencil graphite / lead are conductive. Pen isn't.

Therefore, I suppose, rather than use an optical method of scanning, an completely electrical method could be used.

Although, I doubt they'd do that, it's possible.

Now, I had always thought the pencil number was in relation to its size, as I recall primary school pencils (big thick ones) being "#1". But, I am likely wrong on that.
posted by shepd at 4:47 PM on October 3, 2004

At my school, UGA, the scantrons can read both ink pens and pencils nowadays.
posted by jmd82 at 7:53 PM on October 3, 2004

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