Pardon me, but what does 4/4 mean?
Chances are the first time you stepped foot into a hardwood lumber dealer you saw all these crazy fractions flying at you: 4/4, 5/4, 6/4, 8/4 and so on.
They’re industry terms that not everyone knows, but they refer to the thickness of the lumber. Hardwood lumber thickness is communicated in quarters of an inch.
Let’s start with the most common: 4/4. If we were talking you’d hear me say it as “four quarters,” which is short for four quarters of an inch. If you’re pretty snappy with numbers, you’ve already put together that 4/4 is equal to one inch.
4/4 = 1″ thick
5/4 = 1-1/4″ thick
6/4 = 1-1/2″ thick
8/4 = 2″ thick
12/4 = 3″ thick
There’s another designation that might confuse you: S2S. That means “surfaced two sides.” A saw that cuts lumber from a log is very large and aggressive, so the resulting lumber is known as “rough sawn” and the surfaces of the boards are . . . yes, rough.
Enter S2S. Lumber that is S2S has been planed smooth and flat. Naturally, that process removes some thickness and answers the age old question, “Why isn’t 4/4 lumber a full one inch thick?”
Actual measured thickness on 4/4 lumber that’s S2S is 13/16″. Make sense?
Rough lumber needs to be dressed with a planer and/or jointer and this is where a lumber dealer like ourselves has to make a tough decision. Have the lumber surfaced smooth and clean, or sell it rough? There are benefits to both, but it’s impractical to stock both. Rough lumber costs less, and the woodworker is often able to yield thicker boards. Surfaced lumber, on the other hand, is much easier to see the grain and color when selecting boards, and the woodworker doesn’t necessarily need a planer in order to work with the material, making it easier on the less experienced woodworkers out there.
We’ve decided to stock surfaced lumber.
Here are pictures of each lumber thickness to help you out (left column shows each with a ruler, the right column without):
Tags: hardwoodThis entry was posted on Thursday, November 15th, 2012 at 12:30 pm and is filed under Woodworking Projects. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.