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There is an FAA accepted test of paint film hardness that requires special calibrated pencils, available ONLY from Mitsubishi pencil company, in packages of 17

There is an FAA accepted test of paint film hardness that requires special calibrated pencils, available ONLY from Mitsubishi pencil company, in packages of 17 for $224. Each pencil comes with an individual certificate of calibration shows that it meet's it's specified hardness level. The test is ASTM D 3363, "Standard Test Method for Film Hardness by Pencil Test" https://www.gardco.com/Products/Hardness-Testers/Scratch-Hardness/UNi-JPIA-Pencil-for-Hardness-Testing/c/p-62837?variant=11709 https://www.gardco.com/Products/Hardness-Testers/Scratch-Har...

mrweasel 2y ago
17 to a pack seems like an odd number. Was it originally 18 and then they removed one to keep the price down.
- nedt 2y ago
  In Japan numbers have meaning. Haiku have a 5-7-5 pattern - which gives you 17 as a sum. And saying the number 17 in Japanese sounds like youth and vitality. Might not be so odd after all.
  - dbtc 2y ago
    Well, it will always be odd ;)
    - hartzell 2y ago
      Biggest smile I've had all day... Thank you!
- zck 2y ago
  This pack contains one pencil of each hardness 9H through 6B. There are 17 hardnesses in that range.