Helpful Guide to S4S, S3S, S2S, SLR and RGH
The S4S, S3S, S2S, SLR and RGH terminology are referring to how hardwood lumber has been surfaced. S4S is a board surfaced on four sides with parallel faces and two straight parallel edges. S3S is a board surfaced on three sides with parallel faces and one straight edge. S2S is a board surfaced on both faces with parallel faces. SLR stands for straight line rip meaning a board has one straight edge. RGH stands for rough which would be hardwood lumber yet to be dimensioned.
What does S4S mean in hardwood lumber?
S4S is short for surfaced four sides which means a board has been dimensioned to uniform thickness and width with two parallel faces and two straight parallel edges. S4S hardwood boards usually are sanded to 120 grit on all four sides which allows you to move directly into cutting your parts and assembling your woodworking project. Typically, S4S hardwood lumber is sold in your big box stores such as Lowes or Home Depot and sometimes in small quantities at your local hardwood dealer.
What does S3S mean in hardwood lumber?
S3S is short for surfaced three sides which means a board has been dimensioned to uniform thickness with one straight edge and one rough edge. S3S hardwood lumber allows woodworkers to skip the milling process of a planer and jointer but requires the use of a table saw to rip boards to the desired width. S3S lumber minimizes the time needed to dimension your projects parts by only needing to rip boards to width. You primarily can find S3S lumber at your local hardwood dealer or hardwood lumber yard. Some hardwood dealers are able to SLR or straight-line rip S2S boards for a minimal upcharge providing you with easy-to-use S3S lumber.
What does S2S mean in hardwood lumber?
S2S is short for surfaced two sides which means a board has been dimensioned to uniform thickness with parallel faces and two rough edges. S2S lumber is slightly cheaper than S3S but the cost savings is usually minimal. S2S lumber requires the use of a jointer or a straight line rip jig for a table saw to properly produce a straight clean edge to begin ripping boards to width. S2S lumber is usually found in your local hardwood dealer or hardwood lumber yard. You can also find S2S lumber from local individuals that mill lumber at a smaller scale. I would however caution that some local individuals may not properly mill the lumber to remove twists or warping in the boards.
What does SLR mean in hardwood lumber?
SLR is short for straight line rip which is the process of cutting a clean straight edge on a board. You may also see terms such as SLR1E or SLR2E which stand for straight line ripped one edge and straight line ripped two edges. By having your lumber SLR or straight line ripped you are able to minimize the time needed to edge joint a board using a table saw jig or jointer.
What does RGH mean in hardwood lumber?
RGH is short for rough which means the boards are straight from the lumber mill with no dimensioning. RGH or rough lumber is the cheapest hardwood lumber you can purchase but it requires the most work to produce final S4S boards for your projects. I have purchased rough lumber numerous times from my local hardwood dealer and always felt lucky at the price but sometimes regretted the amount of time involved in milling the lumber as it was significant.
Should you buy S4S hardwood lumber and why?
You should buy S4S hardwood lumber if you have a limited amount of time or lack the tools such as a planer, jointer or table saw. I personally purchased a truckload of S4S lumber to build a crib, dresser, and nightstand when I first started woodworking as I didn’t have the tools needed to mill the lumber. I was able to complete the projects with only minimal tools and saved a ton of time not having to process rough boards. I would however caution purchasing S4S hardwood lumber from your big box stores such as Lowes or Home Depot as they are not normally stored properly. By the big box stores not properly storing kiln dried hardwoods they end up becoming warped, twisted and actually quite hard to work with. My first project was a kitchen table using S4S lumber solely from a big box store that ended up with peaks and valleys on the tabletop due to warped lumber. It had nothing to do with my woodworking skills just poor quality of lumber. When I purchased the S4S lumber to build the crib, dresser, and nightstand I researched to find a regional hardwood dealer that had a warehouse with state of the art climate, and humidity-controlled storage. Finding a quality dealer for S4S lumber will ensure that you do not have unnecessary wood movement in your project.
Should you buy S3S lumber and why?
You should buy S3S hardwood lumber if you have a table saw in your workshop but do not have a jointer or planer. S3S lumber will give you a flexibility to rip hardwood lumber to your desired width rather than purchasing specific boards for your project. Also, S3S lumber is significantly cheaper than S4S and you can purchase from a hardwood dealer in larger quantities for multiple projects at a time.
Should you buy S2S lumber and why?
You should buy S2S hardwood lumber if you have a table saw and jointer or have a straight line rip jig for your table saw. When you purchase S2S lumber you will need to produce a straight edge before you begin ripping the boards to your desired width. I only recommend purchasing S2S lumber if you can quickly create a straight edge preferably with a jointer. The price difference between S2S and S3S lumber is minimal and if you have a large project it would be beneficial to have each board straight lined ripped from your hardwood dealer.
Should you buy RGH or rough lumber and why?
You should buy RGH or rough lumber if you have the time to mill hardwood lumber as well as a planer, jointer, and table saw. If you’re planning to do a few large projects or start woodworking as a long term hobby the savings of purchasing rough lumber could pay for the cost of buying a planer and jointer. Purchasing rough lumber definitely will save you the most money but will also take the longest time to dimension.
Other Useful Lumber Abbreviations
LF - Linear Feet
BF - Board Feet
KD - Kiln Dried
RDM - Random
RL - Random Lengths
RW - Random Widths
RLW - Random Lengths and Widths
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