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Should I Buy S4S or S2S Hardwood?

At Fells Hardwood Supply we mostly carry S2S and S2S SL1E (also called S3S). Rough lumber is uncommon here — only a few exotics come in that way. If you can mill, start with S2S, or S2S SL1E when you want a straight reference edge; you control final thickness and yield, but S2S does not guarantee flatness, so plan to joint and plane. Choose S4S when you want pieces that are already milled and ready to use, and you’re fine paying for that milling plus ending up with less leftover thickness.

Quick reminder of what the letters mean (solid purple edges = milled; dashed = still rough):

2 faces · not flatness

S2S

Faces planed. Does not guarantee flat.

S2S SL1E / S3S

S3S

S2S plus one straight edge.

all 4 sides

S4S

Ready-ish stock; less thickness left.

Choose S2S for control; choose S4S for convenience S2S / S2S SL1E You mill flat & square + more thickness left + control of show faces S4S Already milled 4 sides + ready to use sooner − less leftover thickness
Furniture glue-ups usually want S2S or S2S SL1E so you can true the faces yourself. S4S is the convenience choice when you need face-and-edge ready stock this week.

Choose S2S (or S2S SL1E) when…

  • You’re building tabletops, casework, or anything that must finish dead flat.
  • You want maximum thickness left after flattening cupped stock.
  • You can mill at home, at a makerspace, or you’re ready to learn that workflow.
  • You’re matching grain across several boards and need selection flexibility in the store.

S2S puts the milling decisions in your shop. That usually means better glue-ups and fewer surprises on show faces — if you have (or can borrow) the tools. Ask us if you want help picking boards you’ll mill.

Choose S4S when…

  • You need face-and-edge ready stock for a fast build or trim-style parts.
  • You don’t have surfacing equipment and don’t want a milling step this week.
  • You’re okay with a thinner finished size for the same rough starting quarter.

S4S is a convenience product. Useful — just know what you’re trading away in thickness and control.

Same 4/4 start: S2S leaves more thickness after you mill; S4S arrives thinner Same starting quarter (e.g. 4/4) S2S blank you skim to finished size S4S arrives thinner milling already spent
You pay for milling either way — in shop time or on the ticket. S4S is not free thickness.

Is S4S cheaper because it’s “done”?

Rarely. You pay for the milling one way or another — higher per-board-foot price, a milling fee, or both — and you still use rough nominal thickness in the board-foot tally. “Done” at the store does not mean free.

What if I only have a table saw?

S4S or carefully selected S2S with a known straight edge (or S3S) gets you further. Ask at the counter what’s in stock this week — we can point you at boards that match your tools instead of sending you home with a pile you can’t flatten.

Where do the terms come from?

See the glossary: What do rough, S2S, S3S, and S4S mean? Why S2S still warps: bow, cup, crook, and twist. For the longer milling lesson: Thickness and milling terms.

Related: How hardwood is sold · How much wood do I need? · All FAQs

Fells Hardwood Supply — Hutto, TX — serving Austin, Round Rock, Cedar Park, Georgetown, and the greater Austin metro.