It was the summer of 1952, and the executives of Tombow Pencil were about to revolutionize the Japanese pencil industry—or, possibly, fall flat on their faces. Hachiro Ogawa, the son of founder Harunosuke Ogawa, was Tombow's managing director, and he had just finished a years-long project, at enormous cost...

https://blog.tombowusa.com/2020/07/30/everything-you-need-to-know-about-tombow-pencils/

The following pencils have some qualities, to me at least, that are similar to the Blackwing. They are in no particular order, and please take into account something like this is always subjective.…

Made in Japan with point adjustment:
https://carl-officeproducts.com/products/a-5-royal-pencil-sharpener/

Remove the helical blade from rotor, if you can, by unscrewing the rod that holds it in place. Wear a thick leather glove on one hand. Place 300-400 grit sandpaper strip on hard flat horizontal surface in front of you. Hold one helical blade(cylinder) with long screw through it from the ends between your thumb and middle finger so that blade rotates freely. Lay the helical blade against the sandpaper while holding it. Place two or three fingers of your gloved hand on top of blade to push down against the helical blade. Now pull on helical blade so that it rotates while being pressed down against sandpaper. The blade will bite into the glove and cause it to rotate. Repeat until the blade has rotated a few times. Replace helical blade. I'm sure there are other ways, but that's how I do it.

There is a youtube video of an older man putting the helical blade against a sanding belt. Takes too much metal off.

Goods for the Study is a stationery store in New York City. Their website tells me they have two locations. I visited the “West Village” shop at 50 West 8th Street in late 2022.

https://goodsforthestudy.com/

Blackwing x PMA Diana Pencils

Finished! Ready for the next generation of pencil sharpening! I made a full restoration video of the project which can be found at the link below.
https://youtu.be/EZUwunWWCLA

• The softest is the Blackwing Matte, which is comparable to a 4B pencil. The Matte pencil writes with a smooth, dark line that’s great for shading and drawing.
• Pearl, which has a balanced lead: still dark and soft, but with a harder point that stays sharp longer. The Pearl is similar to a 3B or 2B pencil.
• Blackwing 602, the original Blackwing pencil. Ideal for writing, the 602 has a firm lead that’s a little smoother and darker than that of a typical writing pencil. It’s a versatile pencil whose lead is similar to a B or HB.
• NOTE: I don't really like using the 602. It feels waxy and not dark enough and doesn't stay sharp. KAC 2024-10-09
• Natural - the hardest Blackwing pencil with extra-firm lead. This is a great pencil for writing and for drawing fine lines, and is closest to an HB or H pencil.

For anyone who struggles with sharpening a carpenters pencil, this should help a lot!

The pencil-lead mines of Asiatic Siberia : a historical sketch, 1761-1861 / I.P. Alibert, A.W. Faber.

Jean Pierre Alibert

Riverside Press

http://www.minbook.com/site_files/25-1_EN_p44-55.pdf