Random Lengths
Random lengths means the lumber in a shipment comes in whatever lengths the log and trimming produced, rather than cut to a uniform length. Hardwood lumber is almost always sold in random lengths, typically ranging from 6 to 16 feet. Like random widths, this maximizes yield and minimizes waste at the sawmill.
In-Depth Explanation
Random lengths (abbreviated RL) is the standard for hardwood lumber sales. After a log is sawn into boards, each board is trimmed to remove defects from the ends, resulting in varying lengths. Forcing all boards to a single length would require either trimming long boards shorter (wasting material) or culling short boards (wasting entire pieces). NHLA grading rules specify minimum lengths for each grade — FAS requires a minimum 8-foot length, while lower grades like No. 1 Common accept boards as short as 4 feet. Buyers can sometimes specify a minimum length or a length assortment (e.g., 70 percent 8 feet and longer), though this typically costs extra. Professional woodworkers develop cutting lists before ordering and plan to cut parts from whatever random lengths arrive, nesting shorter parts into shorter boards and longer parts into longer boards to optimize yield. The combination of random widths and random lengths is abbreviated RW/RL.
Usage Example
The random lengths in the walnut delivery ranged from 6 to 14 feet, so the woodworker organized them by length before planning her cuts.