This pencil is a marking tool for timber: a wide wooden body around a wide, flat core. This page explains the pencil itself. Why the width of any pencil line matters, and which edge of it is the dimension, is set out in how to measure and mark accurately; comparing pencils to buy is in how to choose a pencil for woodworking.
Body and core
Makers do not all shape the body the same way. Johnson Level's carpenter pencil is flat, 7 in long and 1/2 in wide, and Johnson says the flat design is easy to grip and will not roll. Staedtler's 148 40 has an oval-hexagonal body 175 mm long. What they share is a core that is wide in one direction and thin in the other, rather than round.
The core is called the lead, and makers use the word, but it contains no lead. McGill University's Office for Science and Society explains that pencil 'lead' is a mixture of graphite and clay, with more graphite making a softer, darker mark; the name goes back to the Romans, who ruled lines with real lead. Grades are each maker's own: Johnson describes its core as medium grade graphite, and Pica offers 2H graphite leads for dry wood in its mechanical version. There is no single grade that every maker uses.
| Pencil | Body | Core | Sharpening |
|---|---|---|---|
| Johnson Level CP | Flat, 7 in long, 1/2 in wide; 'will not roll' | Medium grade graphite | Quick to sharpen, Johnson says |
| Staedtler 148 40 | Oval-hexagonal, 175 mm long | Not stated | Supplied unsharpened, both ends cut for sharpening |
| Pica BIG Dry (mechanical) | 150 mm long | 2 × 5 mm leads; 2H graphite for dry wood | Integrated sharpener |
Each row is one maker's description of its own pencil. Shapes, sizes and grades differ between makers.
Sharpening
A wooden one may come unsharpened — Staedtler supplies the 148 40 with both ends cut, ready to sharpen. A sharpener made for ordinary round pencils is not made for its wide body, so it is sharpened with a knife or with a sharpener made for wide pencils; mechanical ones such as Pica's BIG Dry carry their own sharpener. Rather than a cone, the core is usually brought to a flat, chisel-like edge, which is what lets it mark wide or narrow.
Safety— Sharpening with a knife
If you expose the core with a knife, keep the blade's path away from your body and from the hand holding the pencil, and work on a steady surface. Follow the instructions for any sharpener you use. See woodworking safety equipment and woodworking safety rules.
Marking with it
Held with the core flat to the work, the pencil leaves a broad, easily seen line; turned so its edge meets the work, the same core leaves a narrower one. How wide either line is depends on how the core was sharpened, how far it has worn and how hard it is pressed, so no width is given here. Whichever way you hold it, mark every part the same way and decide which edge of the line is the dimension.
- Where it suits. Rough stock, cutting to length with material left to trim, and marks that have to stay visible while parts are handled. Johnson describes its pencil as durable enough for rough surfaces.
- Where another tool suits better. A line you will saw or pare exactly to — a joint shoulder or a finished length — is better cut with a marking knife, and a line parallel to an edge is better made with a marking gauge. A pencil run along a knife line makes it easier to see.
- Visibility. No colour or grade shows best on every wood: whether a mark is easy to see depends on the wood, its surface, its moisture and the light. The pencil buying guide compares markers and leads made for other surfaces.
What it is not
- A spacer or gauge. Pencils differ in size from maker to maker, and the same pencil wears; a pencil laid between parts gives a gap of whatever that pencil happens to measure, not a known dimension. Set gaps with something of known thickness.
- A scribe. Run along a surface to copy its shape, a pencil leaves a line whose distance from the surface depends on how it is held and how its core is shaped. For a fixed offset, use a scribe or a compass set to the distance; both are in the measuring and layout tools guide.
- A measure of accuracy. The pencil is neither accurate nor inaccurate in itself; its line has width, and whether that matters depends on the job.
Before marking with a wide pencil
- The job can tolerate a pencil line's width, or a knife or gauge will make the final line
- The core is sharpened to an edge and not worn round
- One convention chosen for which edge of the line is the dimension
- The mark shows on this wood and surface
- Gaps set with something of known thickness, not the pencil
- Any knife used for sharpening is kept clear of your body and hands
Sources
Body shapes, sizes, core grades and sharpening provisions are each maker's for its own pencil; they differ, and none is presented as the standard. The width of the line a pencil leaves is not given as a figure: it depends on how the pencil is sharpened, how worn it is and how hard it is pressed. Nothing was tested for this guide.
- 1.
Carpenter Pencil-2/Card (CP). Johnson Level & Tool.
Used for: A 7 in carpenter pencil 1/2 in wide, with a flat design Johnson Level says is easy to grip and will not roll, a medium grade graphite lead that is quick to sharpen, and a body durable enough for rough surfaces.
- 2.
STAEDTLER 148 40 Carpenter Pencil. STAEDTLER.
Used for: A carpenter pencil with an oval-hexagonal body, 175 mm long, supplied unsharpened with both ends cut for easy sharpening.
- 3.
BIG Dry — carpenter's pencil. Pica Marker.
Used for: A mechanical carpenter's pencil with 2 × 5 mm leads, 150 mm long, an integrated sharpener, and graphite leads in hardness 2H for dry wood.
- 4.
Pencils never contained lead. McGill University Office for Science and Society.
Used for: Pencil 'lead' as a mixture of graphite and clay containing no lead, more graphite making a softer, darker mark, and the name traced to the Romans' use of real lead to rule lines.
About this guide
Written by BenchRoot Editorial. How BenchRoot sources, checks and corrects its pages is set out in the Editorial Policy. If something here is wrong or unclear, the contact page explains how to tell us.