Uni-ball Lead Holder Refill - 2 mm - F - Pack of 6

I am new to lead holders and am not an artist. I am engineer that just likes pencils, always searching for the perfect one. I'm pretty sure that I didn't even know that lead came in so many grades until a couple years ago.

This UNI-ball lead in grade F is about as close to a perfect all-around lead as there can be. It seems to reside in that elusive sweet spot where it's dark enough, hard enough, and smooth enough all at the same time.

This lead is not only as dark as an HB, it's as dark as some Bs that are out there, yet smoother and harder. Writing with this lead is quite the revelation is you're used to the cheap Pentel Hi Polymer HM you see in every office supply store for a thinlead (0.5mm, 0.7mm).

Realistically, the difference between this and the UNI in HB is so subtle that I'd choose the F because it's slightly more durable and just a smooth.

I am a rookie at higher end leads (and 2mm products in general), but this impressed me greatly.

This F grade is an excellent writer's lead. It is smooth, dark and slightly oily. Like what the others have said, this lead has the darkness of a B with the wear of an H. This lead gives the writer a glimpse into what the Japanese leads are like such as in the Tombow Mono and Mitsubishi Hi-Uni wooden pencils.

This hard to find graphite grade lead provides excellent control for writing and line sketching since it retains its sharp point longer while producing nice dark marks like an HB grade lead (I recall an article on drafting materials that defined the F grade as having the HB darknes with the hardness of an H lead, yet these Uniball leads are not scratchy at all like some H leads from other manufacturers can be).

While researching for sketching supplies I noticed a lack of reviews everywhere I went. So hopefully this helps someone! Review your purchases people!

I use this lead several times a week when sketching. I use red, blue and black leads while sketching (sometimes all three in one sketch). Red lead is great for value studies!

Pros: Has a great pressure to value ratio (light pressure = light color; hard pressure = dark color). Natural flow of color. Doesn't wear out as fast as other colored lead. Great carrying case (don't take these for granted). Inexpensive.

Personal Cons: Not fully erasable. Marks look more like a classic colored pencil and less like red colored lead.

TL;DR - Surprisingly useful and fun to use. Doesn't erase that well. If you need red lead then you'll be happy!

These leads are individually color-coded (indicating its hardness) with a ring on the end that prevents them from falling off the leadholder. A practical feature I had not seen in decades that prevents accidental drops and lead breakage (when pressing the button absent-mindedly). The leads also fit and work in Staedtler Mars Technico leadholders. I tried fitting them in my Faber-Castell TK 9400 and Caran D'Ache leadholders, but I would have had to snip off the useful stopper ring for them to fit. The leads sharpen easily and glide fairly smoothly over the paper (similar to the graphite from Mitsubishi UniStar pencils and less smoothly that the Hi-Uni grade). Good value for this quality.