The second version of the Modern Fuel mechanical pencil is up on Kickstarter ... It can also fit 0.5mm, 0.7mm, and 0.9mm lead sizes for any of your drawing needs. The pencil comes with an Allen ...

Common mechanical pencils come in sizes to accommodate 0.5, 0.7, and 0.9 mm leads, but there are bigger and smaller ones available. Perhaps one of those really large drafting lead holders could be ...