This post seems to be the antithesis to what I preach all day: "The only good pencil is a wooden pencil! Wooden pencils for life!" Even though 95 percent of my pencil usage is in the form of wood cased pencils, there is still room for a good mechanical. I actually have quite a few mechanical pencils and enjoy using them from time to time. For testing purposes I am using a Tombow MONO graph 0.5mm mechanical pencil and writing on standard printer paper.
Pentel AIN Stein ($3.30 for 40 pcs.)
The Pentel Ain STEIN lead was nice and smooth and had a moderate darkness. Point retention with this lead was moderate. The case it comes in is nice and sleek and the lid stays attached. You twist it to expose a hole where you can get the lead out. STEIN stands for "Strongest Technology by Enhanced SiO2 Integrated Network" (whatever that means). It has an "enhanced reinforced silica core" which claims to make it smooth, strong, and smudge free. Lefties rejoice!
Uni Kuru Toga ($3.30 for 20 pcs.)
The Uni Kuru Toga lead was smooth with a moderate darkness and point retention was a bit better than average. I believe it probably has to do with its special formulation. The Kuru Toga lead has a "soft outer layer around a hard inner core" and they claim that one can easily shape the lead into a point. It comes in a round, cylindrical case with a removable lid. While it is round, there is a small nub on the lid that makes it so it doesn't roll off of a table or desk. This is important to note since the Kuru Toga mechanical pencils do just that. The pencil rotates the lead ever so slightly each time you lift the point off the paper. If you don't have a Kuru Toga pencil, you should buy one!
Pilot Neox ($3.55 for 40 pcs.)
The Pilot Neox lead is nice and smooth ad a bit darker than most other HB lead grades I have tried out. When writing with this lead, it glides across the paper effortlessly. Point retention is on the low average side. Pilot claims this lead contains "high quality graphite with few impurities, and the bond between the carbon atoms is strong than ever." Pilot makes some bold claims here stating that their lead uses lubricating properties of graphite crystal to ensure a smooth writing experience. The canister has a sliding mechanism up to that opens to allow you to pour out the lead.
Uni NanoDia ($3.30 for 40 pcs.)
The Uni NanoDia Low-Wear lead glides easily over the paper as you write and feels very strong and durable. Point retention is very strong considering it is so smooth. The Uni NanoDia Low-Wear Pencil Leads are infused with nano-diamond pieces to create an unusually strong and high-quality lead. The canister has a sliding mechanism in its lid that allows you to dump lead out. I really like the overall design of this container.
Zebra DelGuard ($3.25 for 40 pcs.)
The Zebra DelGuard is moderately dark, but felt kind of scratchy which was disappointing as I usually enjoy Zebra's products. Point retention was average. The case features a clever mechanism that opens a trap door and pushes out leads automatically when you use the slider on the side of the case.
The Pentel Ain STEIN Hard and Soft ($3.30 for 40 pcs.)
I was really excited to see if there was much discernible difference between the soft and hard versions of the Ain STEIN leads. Much to my delight, there was. The soft is a dream to write with as it slides right across the paper and legitimately feels like you are writing with a stick of butter (ok, maybe not that soft). What was interesting was that it seemed lighter than the regular Ain STEIN and hard versions. Perhaps this had to do with how it was laid down on the paper. On the other hand the hard version was semi-scratchy as to be expected, but was slightly darker. Obviously the point retention on the soft was poor and the hard was excellent.
Rotring TIKKY ($3.00 for 12 pcs.)
The Rotring TIKKY lead was beyond disappointing. It was very soft and point retention was awful. What made me ever more frustrated was that you only got TWELVE leads for $3.00! Also, the opening mechanism up to was really hard to fiddle with. The canister is an ugly brown. Avoid this at all costs.
Tombow MONO Graph ($3.25 for 40 pcs.)
The Tombow MONO Graph leads are one of my favorites on this list. They have a hard feeling to them when you write and the lead is nice and strong. Point retention is slightly better than average. These high-quality leads offer smooth writing, crisp lines, and great break resistance. The case features an innovative cap design: sliding it one way allows a single lead to come out a time, and sliding it the other way allows several leads to come out at a time.
Hi-Uni Hi-Density GRCT ($4.95 for 40 pcs.)
I really couldn't find much in the way of a description for the GRCT leads, but I did wander across this great vintage commercial for them:
The Hi-Uni GRCT had the most "pencily" feel out of all the lead I tried. It was also the truest to an HB. Point retention was right in the middle. The case has a sliding mechanism on top that allows you to dump the lead out.
Tombow MONO WX ($3.30 for 40 pcs.)
The Tombow Mono-WX lead was nice and smooth and laid down a medium line. Its point retention was better than average which was surprising considering how smooth it wrote. Also, it felt very strong for a smoother lead which was nice. The top of the unique dispenser opens to the right to dispense a single piece of lead at a time, or can be pushed to the left to extract multiple lead pieces at a time.
Lamy ($4.30 for 12 pcs.)
Another huge disappointment here. I couldn't really find any description about these leads anywhere. They come in an ugly, plain case and have a lid that comes completely off which is annoying because it is small and slippery and can easily be lost. The lead itself is super hard and light. It has a great point retention, but for $4.30 for 12 leads, this is horribly expensive for what you actually get. Avoid.
Staedtler Mars ($2.00 for 12 pcs.)
Staedtler's Mars Micro Carbon lead glides smoothly across paper, producing dark lines. It is kinda flexible and pretty break-resistant. Point retention is a bit below average. According the Staedtler, the lead is also environmentally friendly, composed of more than 90% natural raw materials. Plus, it is produced using unique ecologically-responsible manufacturing processes without PVC or softening agents. The design of the canister is a bit odd and it has a very tiny top that is difficult to remove. You also only get 12 leads and while it is still expensive at $2.00, it is not as sinful as Lamy or Rotring.
Overall, it was fun trying out many different leads. While I didn't rank each one, I have a top three: Tombow MONO graph, Pilot Neox Graphite, and the Pilot Ain STEIN soft. All of these leads were purchased by myself from JetPens and I was not compensated for my opinions at all.