4x4 Post Dimensions Explained: Most lumber is sold in “nominal” (in name only) sizes such as 1x3, 2x4 and 4x4. But these sizes are not the actual dimensions of the wood. The reason for this is that when the 4x4 board is first rough sawn from the log, it's a true 4x4, but the drying/planeing of the board reduces it to a finished 3-5/8 x 3-5/8 size.
All Erva 4x4 disk shaped baffles accommodate this standard and very common 3-5/8 x 3-5/8 size. This is the typical size commonly found at home centers and lumbar yards. More information may be found here: Commercial Lumber Sizes
Rough sawn wood true 4x4 posts are rare. Also, hollow PVC posts may vary in size between 3.75 and 4 inches square. Our 4X4ACT Baffle and T4X4ACT Ground Socket will accommodate true 4x4 posts. Questions? Call 1-800-342-3782.
