per | | | sq.

inch | sq.

inch | | | | | | Hardwoods | | | | | | | | Ash, black | 876 | 832 | | white | 1,360 | 1,312 | | Basswood | 560 | 617 | | Beech | 1,154 | 1,375 | | Birch, yellow | 1,103 | 1,188 | | Elm, slippery | 1,197 | 1,174 | | white | 778 | 872 | | Hackberry | 1,095 | 1,161 | | Hickory, | | | | big shellbark | 1,134 | 1,191 | | bitternut | 1,134 | 1,348 | | mockernut | 1,251 | 1,313 | | nutmeg | 1,010 | 1,053 | | pignut | 1,334 | 1,457 | | shagbark | 1,230 | 1,297 | | water | 1,390 | 1,490 | | Locust, honey | 1,885 | 2,096 | | Maple, red | 1,130 | 1,330 | | sugar | 1,193 | 1,455 | | Oak, post | 1,196 | 1,402 | | red | 1,132 | 1,195 | | swamp white | 1,198 | 1,394 | | white | 1,096 | 1,292 | | yellow | 1,162 | 1,196 | | Sycamore | 900 | 1,102 | | Tupelo | 978 | 1,084 | | | | | | Conifers | | | | | | | | Arborvitae | 617 | 614 | | Cedar, incense | 613 | 662 | | Cypress, bald | 836 | 800 | | Fir, alpine | 573 | 654 | | amabilis | 517 | 639 | | Douglas | 853 | 858 | | white | 742 | 723 | | Hemlock | 790 | 813 | | Pine, lodgepole | 672 | 747 | | longleaf | 1,060 | 953 | | red | 812 | 741 | | sugar | 702 | 714 | | western yellow | 686 | 706 | | white | 649 | 639 | | Spruce, Engelmann | 607 | 624 | | Tamarack | 883 | 843 | |---------------------------------------------| Both shearing stresses may act at the same time.

Thus the weight carried by a beam tends to shear it off at right angles to the axis; this stress is equal to the resultant force acting perpendicularly at any point, and in a beam uniformly loaded and supported at either end is maximum at the points of support and zero at the centre.

In addition there is a shearing force tending to move the fibres of the beam past each other in a longitudinal direction.