Understanding S1S, S2S, S3S, and S4S Lumber: A Woodworker’s Guide

Understanding S1S, S2S, S3S, and S4S Lumber: A Woodworker’s Guide

When shopping for hardwood lumber—especially exotic species like walnut, cherry, or mahogany—you’ll often see terms like S2S, S4S, or S1S listed. These aren’t just codes—they're critical details that tell you how the wood has been milled and how much prep work you'll need to do once it arrives.

Let’s break down each surfacing level so you can make an informed decision for your next build.

What Do S1S, S2S, S3S, and S4S Mean?

These terms stand for "Surfaced [#] Sides", and they refer to how many faces or edges of the board have been planed smooth or straight-line ripped.

🔹 S1S — Surfaced One Side

• One face is planed flat and smooth

• The other face is left rough

• Common use: Slabs or large live edge material where one face is visible

• Great for applications where one side will be glued, routed, or planed further

🔹 S2S — Surfaced Two Sides

• Top and bottom faces are planed flat

• Both edges remain rough

• This is a common base level for furniture and cabinet makers

• Gives you flat stock without losing much thickness

🔹 S3S — Surfaced Two Faces + One Edge

• Same as S2S but with one edge straight-line ripped

• Allows you to start cutting parts to size without jointing

• Ideal for shops without a jointer or those looking to save time

🔹 S4S — Surfaced Four Sides

• Fully milled: top, bottom, and both edges planed and straightened

• Arrives project-ready—just cut to length and build

• Best for quick assembly, small shops, or beginner woodworkers

• Slightly more costly but saves time and tool wear

📦 Why It Matters When Ordering Exotic Lumber

The level of surfacing you choose directly affects:

• Time in your shop

• Tooling requirements

• Waste and material thickness

• Overall cost

At Hardtwood Custom Woodworks, we offer all these options in a range of exotic hardwood species including Walnut, Cherry, Sapele Mahogany, Ash, and more—with optional sanding from 60–120 grit.

Shop our full inventory here:
👉 Hardwood Lumber Collection

🪚 What Surfacing Option Should You Choose?

🧰 Bonus Tip: Add Sanding and Save Even More Time

Want your boards ready for glue-up or finish? You can select sanding up to 120 grit as an add-on. That means less dust in your shop and more time focusing on your craft.

Final Thoughts

Choosing the right lumber milling option is more than just a technical choice—it directly affects your workflow, cost, and end result. Whether you're outfitting a commercial project or crafting a one-of-a-kind piece, understanding S1S through S4S can save you hours of prep and dozens of headaches.

Have questions or custom requirements? Contact us or order hardwood samples to get started.

Related Articles:

• Why Dimensional Exotic Lumber Is the Smart Choice

• Top 10 Hardwood Choices for High-End Projects