[Footnote 8:  Shear should not be confused with ordinary cutting or incision.]

[Illustration:  FIG. 10.—­Example of shear along the grain.]

[Illustration:  FIG. 11.—­Failures of test specimens in shear along the grain.  In the block at the left the surface of failure is radial; in the one at the right, tangential]

|---------------------------------------------|
|                  TABLE VII                  |
|---------------------------------------------|
| SHEARING STRENGTH ALONG THE GRAIN OF SMALL  |
| CLEAR PIECES OF 41 WOODS IN GREEN CONDITION |
|          (Forest Service Cir. 213)          |
|---------------------------------------------|
|                   |    When    |    When    |
|   COMMON NAME     | surface of | surface of |
|   OF SPECIES      | failure is | failure is |
|                   |   radial   | tangential |
|-------------------+------------+------------|
|                   |  Lbs. per  |  Lbs. 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   |