Why Are Carpenters Pencils Flat?

If you do carpentry work, either professionally or as a hobby, you have likely seen and/or used a carpenter’s pencil. These marking tools are not your typical school-grade pencil. Unlike the thin, rounded HB types we are all familiar with, carpenter pencils are thick and have a rectangular shape resembling that of a popsicle stick!

Carpenter’s pencils are flat to prevent them from rolling off (or away) when you put them down on an uneven working surface. They have a thicker, stronger lead that not only resists breaking but also leaves behind a darker, more distinctive mark. This is necessary when working with rough and/or dense building materials such as wood, stone, or concrete.

Why Are Carpenters Pencils Flat?

Now that you know the reason why the carpenter’s pencils are flat, let us explore this topic further and in more detail below. We will discuss why builders use them, how to sharpen them, and where to buy them. I will also explain how wide/thick they are, what pencil grade is best for carpentry work, and which company makes the best types.

We will then explore how these pencils are made, what types of building material they can be used on/for, and how they differ from a mechanical pencil.

* This article may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases.

So, if you are ready to learn all you need to know about carpenter’s pencils, then please continue reading…

Why Do Carpenters Use Flat Pencils?

Unlike traditional pencils, which are usually rounded or hexagon-shaped, carpenter pencils are either elliptical or rectangular-shaped.

They are also extremely durable and perfect for use on the job site. The stronger, thicker lead can be used for marking a variety of building materials including wood, gypsum, plasterboard, stone, and concrete.

A unique ‘bonus’ feature of this pencil: notching out the middle of the lead enables you to draw two parallel cut lines at the same time!

What Jobs Require a Carpenter’s Pencil?

Any job requiring you to mark and/or make cuts in dense building materials will also require the use of carpenter’s pencil.

Professionals such as drywallers, framers, insulators, painters, roofers, joisters, and trim workers use them along with many woodworking hobbyists.

Electricians, plumbers, pipefitters, stonemasons, and concrete/bricklayers also use carpenter’s pencils as part of their daily work routine.

Basically, almost every job in construction will (at some point in time) have need of a carpenter’s pencil.

On What Types of Material Can You Use a Carpenter’s Pencil?

You can use a carpenter’s pencil on almost any building material – wood, gypsum, plasterboard, stone, concrete, and metal (just to name a few)!

It is different than simply using a regular pencil (which is too brittle and fine) or a pen (that often skips or bleeds).

A carpenter’s pencil is the ideal marking tool for almost all construction projects. Not only does the lead last a long time, but it also does not break easily and is cheap for purchase.

How is Carpenter’s Pencil Made?

The traditional versions of the carpenter’s pencil were made by hollowing out pieces of juniper wood. Two wooden halves were carved with a groove down the middle.

A plumbago stick was then placed into the groove and the two halves were glued together.

This is essentially the same method used today – a graphite lead is placed between two pieces of wood (one piece with a narrow groove carved down the middle to hold the lead in place) and then the wood is glued together.

How Do You Sharpen a Carpenter’s Pencil?

The proper way to sharpen a carpenter’s pencil (using a utility knife or chisel) includes the following 5 steps:

  1. Begin by grasping the pencil firmly with your left hand – be sure to allow at least 2 inches of space between your fingers and the end you want to sharpen.
  2. Using a utility knife or chisel, take your right hand and point the sharpening tool down towards the pencil (and, most importantly, away from you) at a 45-degree angle approximately ½ an inch from the end.
  3. Start slicing off the wood on the pencil end (in a whittling or carving fashion), beginning with the narrow sides first and then moving on to the wider sides.
  4. Continue cutting away at the wood until you reach the pencil lead. Be careful not to cut into the lead itself. Stop sharpening once you have exposed at least ¼ of an inch of lead.
  5. To adjust the sharpness of the lead, use a piece of sandpaper – simply drag the tip across the abrasive surface until the desired thickness is achieved.

For a safer, easier alternative, I suggest you purchase a specifically designed carpenter’s pencil sharpener, available both online (through Amazon) or in-store at your local hardware shop.

For more information, please see below under the subheading entitled: What is the Best Carpenter’s Pencil?

How Wide is a Carpenter’s Pencil?

The dimensions of a typical carpenter’s pencil are approximately ¼ of an inch by ¼ of an inch by 7 inches.

The shape and design are essential to the tool’s strength and its ability to withstand not only the heavy-duty construction environment but also the intense pressure applied when marking thick, dense building materials.

The slightly smaller version has a width of about ½ an inch across the flat side and ¼ of an inch along the thin side.

This makes the tool more versatile, allowing it to also be used as a standard width spacer for many construction projects.

Essentially, the dimensions allow the pencil itself to be used as a quick and easy measuring tool or guide.

What Pencil Grade is Best for Carpentry?

Pencils are graded using the graphite scale, which essentially measures the strength of the lead. The best pencil grade for carpentry work is somewhere between a 2H and a 4H, as these will behind a darker, thicker mark.

This especially helpful when working with dense building materials such as wood, stone, and concrete.

What is the Best Carpenter Pencil?

The best carpenter’s pencils are those that are both durable and affordable. A great lot to check out through Amazon is the Misprint Carpenter Pencils. They come in a case of 24 different colors with a unique ‘misprint’ logo or company name on each. The #2 lead is extremely versatile and suitable for a variety of different projects, from artwork to woodwork. Go online and check them out today!


And, to make life easier, instead of using a knife or chisel to sharpen your carpenter pencils, get the Irwin Tools 233250 Carpenter Pencil Sharpener.

Available online through Amazon, this handy gadget is an inexpensive and safe alternative. It uses 50% less pencil per sharpening cycle with a 20% harder blade for a longer life!

The integrated emery board is great for fine point filing while the narrow sharpening angle reduces the risk of lead breaking. Do yourself a favor and check it out today!

What is the Difference Between a Carpenter’s Pencil and a Mechanical Pencil?

A mechanical pencil is a marking tool with a replaceable and mechanically extendable lead, which is usually made of graphite.

It is used to create lines of consistent width on various types of material including paper, plasterboard, and wood.

Unlike a carpenter’s pencil, they rarely (if ever) need sharpening and provide a better balance between precision and break-resistance.

Mechanical pencils are often used for art or woodworking projects. Not only are they less likely break but they often come with a built-in sharpener for ease and convenience.

Even on the roughest of wood, these pencils are strong and durable. They are also available in a variety of lead colors, which is great for marking dark wood such as walnut.


To sum things up, carpenter’s pencils can be found at most woodworking shops and on construction sites.

They are thicker than traditional pencils and flat to prevent them from rolling away. They have a stronger lead (which leaves behind a darker mark) and can be used on a variety of building materials.

Carpenter pencils also act as a spacer for quick measuring of even, repetitive gaps. As well, the width can be used to scribe timber joints in for a perfect fit every time. This makes them the ideal multi-functional and also an essential carpentry tool.

I hope this article has been of help to you. Thanks for reading and good luck with your future woodworking projects.

Cheers, tools owners!


Hi there! My name is Jack and I write for ToolsOwner. I have a passion for everything related to tools and DIY projects around the house. You often find me in my workshop working on new projects.