United States 

Department of 

Agriculture 

Forest Service 

Northeastern Forest 

Experiment Station 

Research Paper NE-628 

Photographic Guide of Selected 

External Defect Indicators and 

Associated Internal Defects 

in White Oak

Everette D. Rast 

John A. Beaton 

David L. Sonderman 
Abstract 

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

defect indicators and assess the effect of the underlying defect on possible end 

products. This guide assists the individual in identifying the surface defect indicator 

and also shows the progressive stages of the defect throughout its development for 

white oak. It illustrates and describes nine types of external defect indicators and 

associated defects that are particularly difficult to evaluate.

The Authors 

EVERETTE D. RAST, research forest products technologist, received a B.S. 

degree in forestry from the University of Missouri in 1960 and an M.S. degree in 

agricultural economics from Ohio State University in 1970. He joined the Forest 

Service in 1960 as a forester on the Mendocino National Forest and transferred to 

the Northeastern Forest Experiment Station, Delaware, Ohio, in 1966. From 1966 

to 1987, he was with the log and tree grade project, and then the management and 

utilization alternatives for non-industrial private forests. In 1987 he was transferred 

to the Station's Forestry Sciences Laboratory in Princeton, West Virginia, as a 

member of the Advanced Hardwood Processing and Technical Resource Center. 

JOHN A. BEATON, forestry technician, received his certificate as a forest 

technician from Lake City Junior College and Forest Ranger School, Lake City, 

Florida, in 1964. He joined the Forest Service in October 1964 as a forestry aid at 

the Forest Insect and Disease Laboratory, Delaware, Ohio. In November 1976, he 

transferred to Project 1351, Northeastern Forest Experiment Station, Delaware, 

Ohio, as a forestry technician. 

DAVID L. SONDERMAN, research forest products technologist, joined the 

Northeastern Forest Experiment Station in 1962 and was on the staff of the 

Eastern Softwood Timber Quality project until 1972. From 1972 to 1987, he was 

located at Delaware, Ohio, with the Northeastern Station's project on 

management and utilization alternatives for non-industrial private forests. He is 

currently with the Station's Forestry Sciences Laboratory at Princeton, West 

Virginia. 

Manuscript received for publication 19 April 1989. 

Northeastern Forest Experiment Station 

370 Reed Road, Broomall, PA 19008 

November 1989
Introduction photographing were saved. Once the veneer started coming

off in a continuous sheet, it was clipped at the notch in the 

small end and stacked by bolts. The bolt number was put on 

the first and last sheet of veneer to identify each bolt. Only 10 

to 15 bolts were sliced at a time so the defects could be 

photographed the same day to prevent stain or discoloration. 

Then the veneer was put in cold storage before drying. 

This photographic guide on white oak is the fourth in a 

series to assist in the understanding of the relationship 

between exterior defect indicators and the underlying 

defect. In this study, like the black walnut study (Rast et 

aI.1988), the slicing of the bolts and photographing the 

interior defects were conducted at the Forest Products 

Laboratory in Madison, Wisconsin. This publication also

provides a stereo pair of photographs of the defect 

indicators to give the user a more realistic view. 

Discussion of Defects

The nine defect indicators reported in this publication are 

suppressed bud; suppressed bud cluster; open and 

occluded bird peck; light, medium, and heavy distortions; 

and new and old wounds. These defects are often difficult 

to identify and evaluate in terms of their effect on endproduct quality. Graders normally have little difficulty

recognizing and evaluating the obvious grading defects 

such as limbs, forks, bumps, or butt scars. 

Procedure 

Sixteen white oak trees located on Vinton Furnace 

Experimental Forest in southeastern Ohio were selected, 

felled, and bucked into thirty-one 4-foot bolts containing the 

defects selected to be studied. Many of the bolts contained 

two or more defects. The bolts were carefully transported to 

a warehouse to be photographed. This controlled 

environment enabled us to take quality defect indicator 

photographs and provided a good storage area for the bolts 

until the film was developed and checked. 

The photo format for each defect evaluated in this publication 

is, first, a pair of stereo photographs of the defect indicator on

the log surface. Next is an enlarged print showing the defect

indicator followed by a series of prints of the actual defect as

it appears at different depths below the log surface. The 

information below the photo of the defect indicator (Fig. 1) 

describes the size of the defect in terms of length (along the

grain), width (across the grain), and height (above the normal 

bark contour); log diameter, inside-thebark at the defect; 

round-up thickness; core diameter; and distance of defect 

above the stump. The information below the interior defect 

(Fig. 1) indicates distance below the log surface (inside the 

bark-ib) as well as the distance from the first full slice of 

veneer to that particular photographed defect. The last 

photograph in each defect series also lists total veneer 

thickness, which is the distance from the initial slice of usable 

veneer to the veneer core. Since the veneer was sliced 1/16

inch thick, and the depth of the defects is reported in 1/1 Oinch intervals, some of the depth figures are identical due to

rounding. 

The ends of the bolts were marked off in quadrants using the 

geometric center as the midpoint. The quadrants were 

aligned to keep all the defects in quadrant 1 or 2 if possible. 

A 1-inch groove was routed along the 3-4 quadrant line, 

providing an identification mark in the rotary-cut veneer for 

clipping. By clipping at this point, each sheet of veneer was 

one complete revolution of the log. This provided a method 

for identifying the correct defects corresponding to the 

surface defect indicators that were photographed. 

Before slicing, the bolts were steam-heated in a water vat to 

loosen the bark. Next the bolts were debarked by hand, 

replaced into the vats, and heated to the correct slicing 

temperature. A bolt was then removed from the vat, chucked 

in the lathe, and rotary sliced into 1/16-inch-thick veneer. 

Before getting a continuous sheet of veneer, the round-up 

pieces of veneer were counted to aid in determining defect 

depth and those selected for 

1 
Suppressed Buds 

Epicormic branches develop from two types of buds: 

suppressed or dormant buds and adventitious buds 

(Kormanik and Brown 1969, Shigo 1986). Suppressed buds

(Fig. 1) can persist for many years just as a bud trace or can

sprout suddenly after some stimulus such as thinning or 

damage to the tree. After sprouting, many develop into 

small limbs that often die, but normally, the bud trace 

continues to form in the cambial zone. The defect indicator is

identified by a slight break in the bark pattern with a small 

protuberance in the center. Adventitious buds, on the other 

hand, form anew from the cambium usually following injury to 

the tree. 

Figure 1.-Suppressed bud 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. . . . . . . . . . . . . . 

1⁄2 x 1⁄2 inch

15.0 inches

0.5 inch 

6.2 inches

7.0 feet 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Depth below—

1.5 inches

1.0 inch 

2 
Depth below— Depth below—

2.5 inches

2.0 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

2.0 inches

1.5 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Depth below— Depth below—

4.3 inches

3.8 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

3.5 inches

3.0 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

3 
Depth below— 

4.5 inches

4.0 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . 

. 

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 4.0 inches

4 
Suppressed Bud Cluster 

As the name implies, a suppressed bud cluster is a group of

suppressed buds (3 to 20) tightly clustered in a small area,

normally less than 2 x 2 inches in size. Usually, there is 

evidence of concentric rings around the defect indicator. 

Figure 2 shows the faint lines of the concentric rings around

the defect indicator and evidence of several individual buds.

Also visible, particularly in the stereo view, are several 

epicormic twigs in the early stages of development. Many

adventitious knots are visible in the first defect photo. 

Figure 2.-Suppressed bud cluster 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. . . . . . . . . . . . 

21⁄2 X 2 inches

11.1 inches 

0.2 inch 

6.1 inches 

9.0 feet 

Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . .

0.6 inch

0.4 inch

5 
Depth below— Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . 

1.0 inch 

0.8 inch

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

1.2 inches

1.0 inch 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

2.2 inches 

2.0 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

2.7 inches 

2.5 inches

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 2.5 inches

6 
Bird Peck 

stages of primary processing of the log (debarking,

slabbing, or round-up). 

Bird peck is evaluated by determining whether callus tissue is 

formed in the peck holes (Rast et al. 1973). If the peck holes

are open, the pecks did not reach the cambium layer and 

there will be no damage; but, if the peck holes are closed, 

there will be damage to the tree. Sometimes bird pecks are 

called old or new. However, this classification should not be 

used except to say that new bird pecks, whether or not they

reach the cambium, can be disregarded in grading logs and 

trees if the tree is cut shortly after injury. The rationale for this 

is that the peck defects will beremoved during the initial 

Figure 3 shows mainly open bird peck that is not occluded. 

However, careful examination of the photograph reveals that

two bird pecks are occluded (in the center of the row pointed 

out by the small arrow). Only one veneer defect photograph 

was taken since the only indication of defects in the wood

was contained entirely in the fourth sheet of veneer (the two 

occluded bird pecks just mentioned above). 

Figure 3.-0pen bird peck. 

Stereo view of defect indicator

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

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

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

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

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

1 x 8 inches 

12.8 inches 

0.0 inch 

6.1 inches 

7.0 feet 

Depth below—

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

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

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 3.3 inches

7 
and the defects in the underlying wood. Severe bird peck 

can lead to a separation of the wood along the rings. 

By contrast, the occluded (closed) bird peck in Figure 4 

shows very clearly the callus material in the pecked hole 

Figure 4.-0ccluded (closed) bird peck and associated internal defects. 

Stereo view of defect indicator

112 x 11 inches Depth below—

12.3 inches 

0.2 inch 

6.1 inches 

12.0 feet 

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

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

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

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

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

1.7 inches 

1.5 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . .

8 
Depth below— Depth below—

1.8 inches 

1.6 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

1.8 inches 

1.6 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Depth below— Depth below— 

1.9 inches 

1.7 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

1.9 inches 

1 .7 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

9 
Depth below— Depth below—

2.1 inches 

1.9 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

2.0 inches 

1.8 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 2.7 inches

10 
Bark Distortions 

distortions (Fig. 6) show more of the concentric circles, but 

they are broken in several areas by flat bark plates or the 

regular bark pattern. Also, there are usually several welldefined breaks in the bark pattern going from the outer edges 

to the center of the defect indicator. Heavy bark distortions 

(Fig. 7) are normally identified by the characteristic pattern of 

concentric circles encompassing the defect indicator and 

pucker-like appearance of the center. 

Bark distortions normally indicate an overgrown knot, and 

because of age they exhibit no height measurement (flush 

with the normal contour of the bark). They are classified as 

light, medium, and heavy. A light bark distortion (Fig. 5) 

shows a slight amount of curvature in the surrounding bark 

plates, and the bark pattern varies only slightly from normal.

Because of these features, light bark distortions are very

inconspicuous and often overlooked. Medium bark 

Figure 5.-Light bark distortion and associated internal defects. 

Stereo view of defect indicator

4 x 4 inches Depth below—

14.1 inches 

0.2 inch 

5.9 inches 

10.0 feet 

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

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

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

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

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

3.5 inches 

3.3 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

11 
Depth below— Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.7 inches 

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

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

4.2 inches 

4.0 inches

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 4.0 inches

12 
If we increase the log diameters at the point of occurrence of 

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

equal to the diameter of the log at the point of occurrence of 

the heavy distortion (Fig. 7), then the depth below the log 

surface to the first sign of the defect would be approximately 

4.0 inches, 2.0 inches, and 0.3 inch, 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 degrade will decrease as the depth to the 

initial defect below the log surface increases. Because of 

greater depth below the log surface, 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. 

Figure 6.-Medium bark distortion 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. . . . . . . . . . . . 

2 X 21⁄2 inches Depth below—

14.8 inches 

0.1 inch 

6.1 inches 

9.0 feet 

1.7 inches 

1.6 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

13 
Depth below— Depth below—

2.6 inches 

2.5 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

2.1 inches 

2.0 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Depth below— Depth below—

4.4 inches

4.3 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

3.1 inches 

3.0 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 4.3 inches

14 
Figure 7.-Heavy bark distortion and associated internal defects. 

Stereo view of defect indicator

11⁄2 X 11⁄2 inches

15.5 inches 

0.2 inch 

6.2 inches 

5.0 feet 

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

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

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

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

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

Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . 

0.5 inch 

0.3 inch

15 
Depth below— Depth below—

1.2 inches 

1.0 inch 

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

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

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

Depth below— Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2.7 inches

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

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2.2 inches

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

16 
Depth below— Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

3.2 inches 

3.0 inches

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

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

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . 4.0 inches

17 
Sound Wounds 

time of year of occurrence, and tree vigor. Sound wounds 

are further classified as new (the defect will be removed 

during slabbing or round-up) and old (the defect extends 

into the quality zone or the heart center). The defect in 

Figure 8, a sound wound (new), 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. 

Wounds can originate from a wide range of causes-an 

individual with a hatchet, a falling limb, or one tree falling 

against another. 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, 

Figure 8.-Sound wound (new) 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. . . . . . . . . . . . 

5 X 11⁄2 inches

13.3 inches 

0.1 inch 

5.9 inches 

9.0 feet 

Depth below—

Log su rface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . .

0.3 inch 

0.2 inch

18 
Depth below— Depth below—

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

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

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

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

Depth below— Depth below—

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

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

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

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

19 
Depth below— Depth below—

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . . . 

0.6 inch 

0.5 inch

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

0.7 inch 

0.6 inch

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . . 3.3 inches

20 
Figure 9 shows a sound wound (old). The main difference is 

that the callus tissue surrounding the "new" wound is even

with or just below the outer bark, has numerous lines running 

perpendicular to the long axis, and has a slight ridge or 

pucker surrounding the seam running lengthwise 

through the defect indicator. By contrast, the callus tissue of

the "old" wound is recessed below the outer bark level, has a

smooth or nearly-smooth surface, and has more of a bark

like fissure running lengthwise through its center. 

One problem for the inexperienced grader is distinguishing

between distortions or overgrown knots and sound wounds. 

The major distinction between the defect indicators of 

distortions or overgrown knots and wounds is the lack of 

concentric circles and the oblong shape associated with 

wounds. 

Figure 9.-Sound wound (old) 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. . . . . . . . . . . . 

3 X 11⁄2 inches

15.0 inches 

0.2 inch 

6.2 inches 

5.0 feet 

Depth below—

Log surface. . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . .. . . . . . . . . . . . 

2.2 inches 

2.0 inches

21 
Depth below— Depth below—

2.7 inches 

2.5 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . .

2.5 inches 

2.2 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . 

Depth below— Depth below—

2.9 inches 

2.6 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . . .

2.8 inches 

2.5 inches

Log surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

First sheet of veneer. . . . . . . . . . . . . . . . . . . . . 

Total Veneer Thickness. . . . . . . . . . . . . . . . . . . . 4.0 inches

22 
Acknowledgments 

The authors wish to thank the Bureau of Vocational 

Rehabilitation, Zaleski Civiran Conservation Corp, Zaleski, 

Ohio, for the assistance provided by their crew during the 

felling and transporting phases of this study. We also wish

to thank personnel at the Forest Products Laboratory for 

their help and cooperation during this study.

23 
References

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.

National Hardwood Lumber Association. 1986. Rules for 

the measurement and inspection of hardwood and 

cypress. Memphis, TN: National Hardwood Lumber 

Association. 118 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. 

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

Wiley & Sons. 367 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. 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.

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

southern hardwood veneer logs and bolts. Res. Pap. 

SE-19. Asheville, NC: U.S. Department of Agriculture, Forest

Service, Southeastern Forest Experiment Station. 23 p. Rast, Everette D.; Beaton, John A.; Sonderman, David L. 

1988. Photographic guide to selected external defect 

indicators and associated internal defects in black walnut. 

Res. Pap. NE-617. Broomall, Pa: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest Experiment

Station. 24 p. 

Kormanik, Paul P.; Brown, Claud L. 1969. Origin and 

development of epicormic branches in sweetgum. Res. 

Pap. SE-54. 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. NE1. 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. 

Shiga, 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. 1989. Photographic guide of

selected external defect indicators and associated internal defects in white oak. 

Res. Pap. NE-628 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 assists the individual in identifying the surface defect indicator and also shows the 

progressive stages of the defect throughout its development for white oak. It illustrates 

and describes nine types of external defect indicators and associated defects that are 

particularly difficult to evaluate. 

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

Keywords: Defect identification; photo guide; white oak; quality

 assessment. 

25 
Headquarters of the Northeastern Forest Experiment Station is in Broomall, 

Pennsylvania. 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 

Harnden, Connecticut, in cooperation with Yale University

Morgantown, West Virginia, in cooperation with West Virginia University

Orono, Maine, in cooperation with the University of Maine 

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

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. 

26