Figure 6.-Medium bark distortion and associated internal 

Stereo view of defect indicator 

Defect size................................................................ 

Log diameter at defect (ib) ...................................... 

Round-up thickness ................................................

Core diameter .........................................................

Defect distance above stump .................................

3 x 3 inches 

13.5 inches 

0.5 inch 

6.3 inches 

21.0 feet 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2.0 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 inches 

12
Depth below Depth below

Log surface. . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. 3.0 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . .. 2.5 inches 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.5 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 inches 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7 inches 

Total Veneer Thickness - 3.7 inches 

13
are equal to the diameter of the heavy distortion (Fig. 7), then the 

depth below the log surface to the first sign of the defect would be 

approximately 5.0 inches, 3.5 inches, and 1.5 inches, respectively. 

This clear area between the log surface and the defect is very

important in determining product suitability and, therefore, the log's 

economic value.

All bark distortions will result in some product degrade, but the 

amount of degraae-will decrease as the depth to the initial defect 

below the log surface increases. Light bark distortions are not 

considered defects in grading factory lumber logs, but medium and 

heavy distortions are. Likewise, many of the grading systems for 

veneer logs disregard light bark distortions. If we increase the log 

diameter for the light and medium distortions (Figs. 5 and 6) so they

Figure 7.-Heavy bark distortion and associated internal defects. 

Stereo view of defect indicator 

2 x 2 inches Depth below

16.5 inches 

0.0 inch 

6.2 inches 

10.0 feet 

Defect size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Log diameter at defect (ib) . . . . . . . . . . . . . . . . . . . . . 

Round-up thickness . . . . . . . . . . . . . . . . . . . . . . . . . . 

Core diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Defect distance above stump . . . . . . . . . . . . . . . . . . . 

Log surface. .. .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . .. 1.5 inches 

14
Depth below Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 inches 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4.0 inches 

First sheet of veneer . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 inches 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 inches 

Total Veneer Thickness - 6.0 inches 

15
Sound Wound 

Wounds can originate from a wide range of causes-from the 

individual with a hatchet to a limb or another tree falling against the 

tree. Wounds are classified into two categories: sound and unsound.

Sound wounds mayor may not be grade defects depending on their 

age and depth. If a wound is recent and can be slabbed off during 

sawing or if it is very deep and falls in the heart center of the log 

(Rast et al. 1973), then it results in very little degrade. Whether a 

wound becomes unsound depends on the type, severity, time of year 

of occurrence, and tree vigor. The defect in Figure 8 was probably a 

clean, smooth removal of the bark and possibly some wood on a 

fast-growing tree because the first and last evidence of the defect in 

the veneer is contained within one-half inch. The major distinction 

between the defect indicators of overgrown knots and wounds is the

lack of concentric circles associated with wounds.

Figure 8.-Sound wound and associated internal defects. 

Stereo view of defect indicator 

Defect size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Log diameter at defect (ib) . . . . . . . . . . . . . . . . . .

Round-up thickness . . . . . . . . . . . . . . . . . . . . . . . 

Core diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Defect distance above stump . . . . . . . . . . . . . . . . 

4 x 2 inches 

18.3 inches 

0.5 inch 

6.5 inches 

6.0 feet 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 inches 

16
Depth below Depth below

Log surface. . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. 4.3 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . .. 3.8 inches 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.4 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . .3.9 inches 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 inches 

Total Veneer Thickness - 6.0 inches 

17
Hole 

Holes caused by woodpeckers can be very serious to all trees or 

logs, but they usually occur only on trees that have serious decay

problems. When woodpeckers attack healthy trees and make only an

abortive attempt of producing a large hole (Fig. 9), then the physical 

damage is usually minimal. As this example shows, the hole only

penetrated seven tenths of an inch into the wood. Even though this 

was a fairly recent attack, stain has already begun to spread both

above and below the hole. These holes make an excellent entrance

for insects and pathogens. 

Figure 9.-Hole (woodpecker) and associated internal defects. 

Stereo view of defect indicator 

Defect size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Log diameter at defect (ib) . . . . . . . . . . . . . . . . . . 

Round-up thickness . . . . . . . . . . . . . . . . . . . . . . 

Core diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Defect distance above stump . . . . . . . . . . . . . . . 

1 x 1 inch 

15.2 inches 

0.0 inch 6.5 

inches 10.0 

feet 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.3 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 inch 

18
Depth below Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 inch 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.5 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.5 inch 

Depth below Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.6 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.6 inch 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.7 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.7 inch 

Total Veneer Thickness - 4.2 inches 

19
Gunshot (Slug) Damage 

This defect indicator-is very similar in appearance to certain insect 

attacks. The gunshot indicator (Fig. 10) is nearly circular and has an

almost smooth surface, whereas insect defect indicators that have 

healed over are larger in size, and more oblong in shape with a ripply 

surface and a seam-like line running through the center of the defect 

indicator. Gunshot wounds have very little stain if the bullet is lead. 

Also, the hole closes fairly rapidly and is not kept open for a period of

time like those of insects. Gunshot wounds can be doubly damaging 

particularly in veneer logs. As in this example, the defect affected 1

% inches of veneer and also can be potentially damaging to the 

veneer knife depending on the type of bullet. 

Figure 10.-Gunshot (slug) and associated internal defects. 

Stereo view of defect indicator 

Defect size . . . . . . . . . . . . . . . . . . . . . . . . . . 

Log diameter at defect (ib) . . . . . . . . . . . . . . 

Round-up thickness . . . . . . . . . . . . . . . . . . . 

 Core diameter . . . . . . . . . . . . . . . . . . . . . . . 

Defect distance above stump . . . . . . . . . . . . 

1 x 1 inch 

18.0 inches 

0.0 inch 

6.6 inches 

4.5 feet 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.5 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.5 inch 

20
Depth below Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.0 inch 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 inch 

Log suriace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.5 inches

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 inches

Depth below Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 inches 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.6 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . .1.6 inches 

21
Depth below Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.8 inches 

First sheet of veneer.. . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 inches 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.9 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . .1.9 inches 

Depth below

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2.0 inches 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . . . .2.0 inches 

Total Veneer Thickness - 6.0 inches 

22
Acknowledgments 

The authors wish to thank the Walnut Council for their 

assistance and encouragement and in particular the Hardwood

Forestry Educational Fund, Inc. for their grant to aid 

in the completion of this research. We also wish to thank the Ohio

Department of Natural Resources (ODNR) and the

Forest Products Laboratory for their help and cooperation during 

this study. In particular, we wish to thank Mike Long (ODNR) and 

the staff of Tar Hollow State Forest (Ohio) for their assistance. 

23
References

National Hardwood Lumber Association. 1986. Rules for the 

measurement and inspection of hardwood and cypress. 

Memphis, TN: National Hardwood Lumber Association. 118 p. 

Butin, Heinz; Shigo, Alex L. 1981. Radial shakes and "frost

cracks" in living trees. Res. Pap. NE-478. Broomall, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 21 p. 

Esau, Katherine. 1965. Plant anatomy. New York: John Wiley

& Sons. 367 p. Rast, Everette D. 1982. Photographic guide of selected external 

defect indicators and associated internal defects in northern 

red oak. Res. Pap. NE-511. Broomall, PA: U.S. Department of

Agriculture, Forest Service, Northeastern Forest Experiment 

Station. 20 p. 

Harrar, E.S. 1954. Defects in hardwood veneer logs: their

frequency and importance. Res. Pap. SE-39. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, Southeastern

Forest Experiment Station. 45 p. 

Harrar, E.S.; Campbell, R.A. 1966. The major defects in southern

hardwood veneer logs and bolts. Res. Pap. SE19. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 23 p. 

Rast, Everette D.; Beaton, John A. 1985. Photographic guide to

selected external defect indicators and associated internal 

defects in black cherry. Res. Pap. NE-560. Broomall, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 22 p. 

Kormanik, Paul P.; Brown, Claud L. 1969. Origin and development of epicormic branches in sweetgum. Res. Pap. SE54. Asheville, NC: U.S. Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 17 p. Rast, Everette, D.; Sonderman, David L.; Gammon, Glenn L. 1973. 

A guide to hardwood log grading. Gen. Tech. Rep. NE-1.

Upper Darby, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Forest Experiment Station. 32 p. Lockard, C.R.; Putnam, J.A.; Carpenter, R.D. 1963. Grade defects 

in hardwood timber and logs. Agric. Handb. 244. Washington, 

DC: U.S. Department of Agriculture. 39 p. 

Lutz, John F. 1971. Wood and log characteristics affecting 

veneer production. Res. Pap. FPL-150. Madison, WI: U.S. 

Department of Agriculture, Forest Service, Forest Products 

Laboratory. 31 p.

Shigo, Alex L. 1986. A new tree biology dictionary. Durham, 

NH: Shigo and Trees, Associates. 132 p. 

Shigo, Alex L.; Larson, Edwin vH. 1969. A photo guide to the 

patterns of discoloration and decay in living northern

hardwood trees. Res. Pap. NE-127. Upper Darby, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 100 p. 

Marden, Richard M.; Stayton, Charles L. 1970. Defect indicators 

in sugar maple-a photographic guide. Res. Pap. NC-37. S1. 

Paul, MN: U.S. Department of Agriculture, Forest Service, North 

Central Forest Experiment Station. 29 p. 

24
Rast, Everette D.; Beaton, John A.; Sonderman, David L. 1988. Photographic guide to selected 

extemal defect indicators and associated intemal defects in black walnut. Res. Pap. NE-617. 

Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment 

Station. 24 p. 

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and 

assess the effect of the underlying defect on possible end products. This guide aids the individual in 

identifying the surface defect indicator and also shows the progressive stages of the defect throughout 

its development for black walnut. It illustrates and describes 10 types of external defect indicators an

associated defects that are particularly difficult to evaluate. 

d

ODC 852.1/.12/.13/.17/.19-(084.121) 

Keywords: Defect identification; photo guide; black walnut; quality

 assessment. 
Headquarters of the Northeastern Forest Experiment Station are in Broomall, Pa. Field 

laboratories are maintained at: 

• Amherst, Massachusetts, in cooperation with the University of Massachusetts. 

• Berea, Kentucky, in cooperation with Berea College. 

• Burlington, Vermont, in cooperation with the University of Vermont. 

• Delaware, Ohio. 

• Durham, New Hampshire, in cooperation with the University of New Hampshire. 

• Hamden, Connecticut, in cooperation with Yale University. 

• Morgantown, West Virginia, in cooperation with West Virginia University, Morgantown.

• Orono, Maine, in cooperation with the University of Maine, Orono. 

• Parsons, West Virginia. 

• Princeton, West Virginia. 

• Syracuse, New York, in cooperation with the State University of New York College of

Environmental Sciences and Forestry at Syracuse University, Syracuse. 

• University Park, Pennsylvania, in cooperation with the Pennsylvania State University. 

• Warren, Pennsylvania. 

Persons of any race, color, national origin, sex, age, religion, or with any handicapping condition are welcome to use and enjoy all facilities, programs, and services of 

the USDA. Discrimination in any form is strictly against agency policy, and should 

be reported to the Secretary of Agriculture, Washington, DC 20250.