Editing Lumber (section)

===North American hardwoods===
In North America, market practices for dimensional lumber made from hardwoods{{efn
  |Because working expensive hardwoods is far more difficult and costly, and because an odd width might well be conserved and be of use in making such surfaces as a cabinet side or tabletop [[jointer|joined]] from many smaller widths, the industry generally only does minimal processing, preserving as much board width as is practicable. This leaves culling and width decisions totally in the hands of the craftsman building [[cabinetry|cabinets]] or furniture with the boards.
  }} varies significantly from the regularized ''standardized '[[dimension lumber]]' sizes'' used for sales and specification of softwoods – hardwood boards are often sold totally rough cut,{{ efn
 | In quarter sawn thicknesses, meaning the thickness and width dimensions as they come out of the sawmill's table. Because lengths vary most with temperature, hardwood boards in the US often have a bit of extra length.
 }} or machine planed only on the two (broader) face sides. When hardwood boards are also supplied with planed faces, it is usually both by random widths of a specified thickness (normally matching milling of softwood dimensional lumber) and somewhat random lengths. But besides those older (traditional and normal) situations, in recent years some product lines have been widened to also market boards in standard stock sizes; these usually retail in [[big-box store]]s and using only a relatively small set of specified lengths;{{efn
  |Small set of specified lengths: Fixed-length hardwood boards in the United States are most common in {{convert|4|–|6|ft|abbr=on}} lengths, with a good representation of {{convert|8|ft|abbr=on}} lengths in a variety of widths, and a few widths with occasional dimensional sizes to {{convert|12|ft|abbr=on}} lengths. Often the longer sizes need be special ordered.
  }} in all cases hardwoods are sold to the consumer by the [[board-foot]] ({{convert|144|cuin|disp=or}}), whereas that [[measurement system|measure]] is not used for softwoods at the retailer (to the cognizance of the buyer).{{efn
  |name=On Australia|1= Fixed board lengths do not apply in all countries; for example, in Australia and the United States, many hardwood boards are sold to timber yards in packs with a common width profile (dimensions) but not necessarily consisting of boards of identical lengths.}}

{| class="wikitable" style="text-align:center"
|+ North American hardwood dimensional lumber sizes
|-
! Nominal (rough-sawn size)
! S1S (surfaced on one side)
! S2S (surfaced on two sides)
|-
| {{frac|1|2}} in
| {{convert|3/8|in|abbr=on}}
| {{convert|5/16|in|abbr=on}}
|-
| {{frac|5|8}} in
| {{convert|1/2|in|abbr=on}}
| {{convert|7/16|in|abbr=on}}
|-
| {{frac|3|4}} in
| {{convert|5/8|in|abbr=on}}
| {{convert|9/16|in|abbr=on}}
|-
| 1 in or {{frac|4|4}} in
| {{convert|7/8|in|abbr=on}}
| {{convert|13/16|in|abbr=on}}
|-
| {{frac|1|1|4}} in or {{frac|5|4}} in
| {{convert|1+1/8|in|abbr=on}}
| {{convert|1+1/16|in|abbr=on}}
|-
| {{frac|1|1|2}} in or {{frac|6|4}} in
| {{convert|1+3/8|in|abbr=on}}
| {{convert|1+5/16|in|abbr=on}}
|-
| 2 in or {{frac|8|4}} in
| {{convert|1+13/16|in|abbr=on}}
| {{convert|1+3/4|in|abbr=on}}
|-
| 3 in or {{frac|12|4}} in
| {{convert|2+13/16|in|abbr=on}}
| {{convert|2+3/4|in|abbr=on}}
|-
| 4 in or {{frac|16|4}} in
| {{convert|3+13/16|in|abbr=on}}
| {{convert|3+3/4|in|abbr=on}}
|+
|}

Also in North America, hardwood lumber is commonly sold in a "quarter" system, when referring to thickness; 4/4 (four quarter) refers to a {{convert|1|in|mm|adj=mid|-thick}} board, 8/4 (eight quarter) is a {{convert|2|in|mm|adj=mid|-thick}} board, etc. This "quarter" system is rarely used for softwood lumber; although softwood decking is sometimes sold as 5/4, even though it is actually one inch thick (from milling {{convert|1/8|in|abbr=on|disp=or}} off each side in a motorized [[thickness planer|planing]] step of production). The "quarter" system of reference is a traditional North American lumber industry nomenclature used specifically to indicate the thickness of rough sawn hardwood lumber.

In rough-sawn lumber it immediately clarifies that the lumber is not yet milled, avoiding confusion with milled dimension lumber which is measured as actual thickness after machining. Examples – {{frac|3|4}}-inch, 19&nbsp;mm, or 1x. In recent years{{when|date=February 2020}} architects, designers, and builders{{who|date=September 2023}} have begun to use the "quarter" system in specifications as a vogue of insider knowledge, though the materials being specified are finished lumber, thus conflating the separate systems and causing confusion.

Hardwoods cut for furniture are cut in the fall and winter, after the sap has stopped running in the trees. If hardwoods are cut in the spring or summer the sap ruins the natural color of the lumber and decreases the value of the wood for furniture.