3.1: Reading Grain Direction

3.1 Reading Grain Direction

Rough lumber is rarely flat, straight, square, or exactly the size you need. Before it can become part of a woodworking project, it must be milled.

Milling is the process of creating reliable reference surfaces and bringing a board to its required thickness, width, and length.

In this chapter, you will work with several of the primary machines used to prepare rough lumber:

• radial arm saw;
• jointer;
• planer; and
• table saw.

You will also learn the standard Eight Steps to Squaring Lumber, which brings these machines together into a logical milling sequence.

Before using any machine, you must receive instruction from your instructor and follow the WMT Wood Lab Safety Manual. The information in this chapter prepares you to better understand machine demonstrations and milling procedures; it does not replace hands-on instruction or required machine checkouts.

Additional Resource

If you would like more detail about common woodworking machines, Peter Scheidt’s Introduction to Woodworking Machines (opens new window) is available as a supplemental open resource.

It provides additional explanations of woodworking machines, their parts, and common operations. Use it to reinforce what you learn in class or to review a machine before working in the shop.

When working in the Cerritos College woodshop, always follow the WMT Wood Lab Safety Manual and your instructor’s directions.

Learning Outcomes

After completing this section, you should be able to:

• Explain why grain direction matters when surfacing lumber.
• Use face grain and end grain to estimate a good feed direction.
• Recognize that grain direction may change within a board.
• Explain what to do when the grain pattern is unclear.

Cutting With the Grain

Wood has direction.

Because the fibers in a board do not always run perfectly parallel to its surfaces, the direction you feed a board through a cutting machine can affect the quality of the surface you produce.

When a cutting edge moves through wood, the best results usually occur when the cutter works with the grain.

When the cutter works against unfavorable grain, fibers may lift ahead of the cutting edge and break away below the intended surface.

This damage is called tearout.

Tearout is especially important when using machines such as the:

• jointer;
• planer; and
• router.

The grain in real lumber can be complicated, so there is no method that works perfectly every time. The goal is to learn how to make an informed first choice.

Look at the Face Grain

Many flatsawn boards show curved grain patterns commonly called cathedrals.

Imagine an arrow following the direction of the cathedral pattern.

That imaginary arrow has a point and a tail.

Do not use the face grain by itself to determine feed direction. The end grain provides additional information.

Look at the End Grain

Now look at the end of the board.

Imagine another arrow following the direction of the growth rings.

Again, that arrow has a point and a tail.

Compare the imaginary arrow on the face with the imaginary arrow on the end.

The Point-to-Point / Tail-to-Tail Method

As a starting point, feed the board so that:

• tail meets tail, or
• point meets point.

These orientations usually indicate a favorable direction for jointing or planing.

When you see:

• point to tail, or
• tail to point,

feeding from the opposite end will usually give a better result.

Four boards showing face-grain and end-grain arrows used to estimate feed direction. Tail-to-tail and point-to-point arrangements indicate the preferred direction for jointing or planing, while point-to-tail and tail-to-point indicate feeding from the opposite end.

Figure: Surfacing Lumber and Grain Direction

Real Wood Is Not Always Cooperative

The grain may:

• reverse direction;
• curve around a knot;
• change within a single board;
• contain figure that makes the direction difficult to read; or
• show little or no cathedral pattern.

When the direction is unclear, inspect the board carefully and make a light first cut.

If one direction produces excessive tearout, stop and try the opposite direction when the operation allows it.

Experience matters. The more lumber you machine, the better you will become at recognizing grain direction before making a cut.

Check Yourself

1. Why does grain direction matter when machining wood?
2. What is tearout?
3. What two surfaces can help you estimate grain direction?
4. What does the point-to-point / tail-to-tail method tell you?
5. What should you do when the grain direction is unclear?