Mechanical Pencil Lead Sizes & Lead Types

The humble mechanical pencil might not be as flashy as the gold-nibbed fountain pen. Yet, it is a hard-working, trusted creative tool. Professionals from many fields do important work with a pencil in hand. In this article, we hope to guide you toward the perfect pencil for your sketching, writing, and drawing needs. You'll become familiar with types of mechanical pencils, the range of lead sizes as well as the lead hardness grades.

Types of Mechanical Pencils

Mechanical pencils can be divided into two categories by the basic types of mechanism - those that only hold the lead in position and those that hold and propel the lead.

Pencils that hold and propel the lead are the most popular for everyday writing, sketching and technical drawing. These pencils can be further classified by two different mechanisms - ratchet and screw.

Ratchet-based pencils advance the lead one small step at a time. Each time you activate the pencil's mechanism, the lead advances in a fixed increment.

Here are a several examples of common ratchet-based mechanical pencils.

  • Push button
    A button usually located on the top or side of the pencil is the most common method for advancing the lead. This is the most common type of ratchet-based pencils. The Caran d'Ache 844 pencil seen here is an example of a push-button, ratchet mechanical pencil.
  • Shaker
    When the pencil is shaken (not stirred), a weight inside of the pencil's body operates the advancing mechanism.
  • Twist
    When a part of the mechanical pencil's body is twisted round (it then springs back), a cam and a push rod advances the lead.
  • Automatic lead advance
    As the tip of the pencil touches the paper, the lead automatically advances replace the worn section. The Uniball Kuru Toga is a popular example of this type of mechanism.

Screw-based pencils advance the lead by twisting some part of the upper body or the pencil tip. The mechanism is wound around internally to move the lead. The lead is advanced continuously by the screw thread. It is not advanced in increments like ratchet mechanisms. In the early 20th Century, this was the most common type of hold-and-propel pencil mechanism.

The Retro 51 Tornado Pencil is one of our most popular mechanical pencils that uses the screw-based mechanism. Twisting the knurled top smoothly slides the 1.15mm lead out from the front nosecone. To retract the lead, the user turns the knurled top in the opposite direction.

The second category of mechanical pencils hold the lead in position. They are frequently referred to as leadholders or clutch pencils. These types of pencils typically use a thicker lead (commonly 2-5mm in diameter), but many other sizes are also used. Pencils in this category have a set of jaws that clamp the lead at the tip. The jaws are typically opened by pressing down the top cap. This allows the lead to freely drop through the barrel. They can only carry one whole stick of lead at a time. Similarly to wooden pencils, the thick leads of leadholders require frequent sharpening by the user to enable fine lines to be drawn. Some pencils, like the Caran d'Ache Fixpencil, will have a built-in lead sharpener underneath the push-button cap.

The Kaweco Sport 3.2mm Clutch Pencil shown here has a clear, demonstrator design to show the mechanism in action.

Mechanical Pencil Lead Sizes and Hardness

Just like the sheet of paper they sketch upon, pencil leads are two-dimensional. When you are selecting the lead for your pencil, be aware of its hardness and the diameter size.

Lead hardness indicates how dark of a mark you can make while using the same finger pressure. To produce the scale below, we tested 12 different pencil leads using the same amount of tip pressure on the page.

As you may know already, pencil lead isn't made of lead. It's made of graphite. Pencil manufacturers mix graphite with either clay or polymer, depending on the lead size and hardness. The blending of materials results in the various hardness grades you see in the scale below.

The higher the number next to the "H," the harder the lead is. The higher the number next to the "B," the softer the lead is. The hardest leads produce the lightest lines with the same finger pressure it takes to create dark lines using the softest leads.

Tone and Grade Character Uses

B / #1

Soft

Freehand drawing

HB / #2

Medium

Writing / Linear Drawing

F / #2 1/2

Medium

Writing / Linear Drawing

H / #3

Hard

Technical / Mathematical Drawing

2H / #4

Hard

Technical / Mathematical Drawing

Remember the trusty #2 pencil? That is actually a reference to the American lead hardness scale. It is considered to be the equivalent of "HB" - not too hard, yet not too soft. Perfect for filling in the bubbles of scan sheets.

Harder (H) leads are better suited for technical drafting and under-drawings. The lighter value is easier to erase. They are also harder to smudge, making H-leads ideal for lefties. Illustrators use a hard lead to lay out the shapes and composition of the drawing. Then, the shapes would be defined in softer leads or with ink to create more contrast.

Softer (B) leads are smoother and draw a darker line. Rapidly sketch an outdoor park scene or capture the gesture of a person riding the train. Leads softer than 4B require less finger pressure to make a darker mark. Artists can fill in large areas of value quicker with a soft lead. They are easier to smudge to blend gradients on the page.

Depending on how you intend on using the pencil, the lead diameter plays a major role in selecting a mechanical pencil, moreso than lead hardness. Mechanical pencil mechanisms are fixed for the type of lead they accept. This means that a 0.7mm mechanical pencil only accepts 0.7mm diameter lead. While it is possible to use different lead hardnesses (2B, HB, or 2H, for example) in the same lead diameter, it is not possible to switch a different lead diameter (like putting a 0.9mm in a 0.5mm pencil) in a mechanical pencil.

Thinner leads under 0.7mm are best suited for light, technical drawings, drafts, and fine details. The lines will appear lighter on the paper and are easier to erase. Thinner leads are ideal for those who have small, neat handwriting.

Leads between 0.9mm and 1.4mm are suitable for general purpose writing and sketching. In the fountain pen world, these would be your "medium" point sizes available on most pens.

Leads above 2mm are usually considered "sketch" mechanical pencils that clutch the larger piece of lead. Although the lead is measured by its diameter, the point is sharpened and will require a sharpener to control the line thickness. An artist may use the lead on the side of the point to fill in large areas of value.

Why Choose a Mechanical Pencil over a Typical Woodcase Pencil?

Woodcase pencils are 100% consumable and disposable. To use one, a sharpener is required. Each time you sharpen a wood pencil, you shave away a piece of your writing tool. At the end, a woodcase pencil can be sharpened to the point (pun intended) where the pencil is too short to write comfortably. Thus, the user cannot effectively use 100% of the pencil, disposing of the stub when it becomes too small. Also, without using a pocket protector or pencil cap, putting a sharpened pencil in your pocket can lead to a hole in your favorite shirt or bodily harm if you accidently poke yourself with the tip.

In contrast to the consumable wood pencil, the mechanical pencil can write forever as long as the lead is replaced. Mechanical pencils under 0.7mm in lead diameter deliver a consistent line without needing a sharpener. Instead of discarding the pencil when it becomes too small to use, each stick of mechanical pencil lead can be used almost all the way until the mechanism can no longer hold the graphite. Mechanical pencils are much more pocket friendly, as they typically have a pocket clip and the lead can be retracted to hide inside the pencil when not in use.

Finding the right mechanical pencil for you

Similar to the range of nib options available with fountain pens, mechanical pencils provide the user with a tool tailored to their work. By carefully selecting the lead diameter and lead hardness, the writer/artist can fine tune their pencil to best suit their needs. Whether you're drafting the floor plans to an office building or casually sketching a city skyline, there's an ideal pencil for you. And, perhaps it isn't just one pencil. Much like a painter has an assortment of brushes to fill a canvas, a creative artist will employ an assortment of pencils is varying lead hardnesses and diameters to create a piece.

So, while there isn't any one right answer for "what is the best mechanical pencil?," you can find the world's best writing tools on Goldspot Pens and find one (or five) that best fit your needs. Explore our various mechanical pencil options, refill leads, and erasers at our store.